Title: Physiological economy in nutrition, with special reference to the minimal proteid requirement of the healthy man
Author: R. H. Chittenden
Release date: November 28, 2022 [eBook #69439]
Language: English
Credits: Mark C. Orton and the Online Distributed Proofreading Team at https://www.pgdp.net (This file was produced from images generously made available by The Internet Archive)
PHYSIOLOGICAL ECONOMY
IN
NUTRITION
WITH SPECIAL REFERENCE TO THE MINIMAL
PROTEID REQUIREMENT OF THE
HEALTHY MAN
AN EXPERIMENTAL STUDY
BY
RUSSELL H. CHITTENDEN,
Ph.D., LL.D., Sc.D.
DIRECTOR OF THE SHEFFIELD SCIENTIFIC SCHOOL OF YALE UNIVERSITY
AND PROFESSOR OF PHYSIOLOGICAL CHEMISTRY; MEMBER OF THE
NATIONAL ACADEMY OF SCIENCES; PRESIDENT OF THE
AMERICAN PHYSIOLOGICAL SOCIETY; MEMBER OF
THE AMERICAN PHILOSOPHICAL SOCIETY, ETC.
NEW YORK
FREDERICK A. STOKES COMPANY
1907
Copyright, 1904,
By Frederick A. Stokes Company
Published in November, 1904
THE UNIVERSITY PRESS, CAMBRIDGE, U. S. A.
Facing page | |
Group of soldiers at work in the Gymnasium | 136 |
Side view of Fritz | 198 |
Back view of Fritz | 204 |
Front view of Coffman and Steltz | 212 |
Back view of Coffman and Steltz | 220 |
Side view of Zooman and Cohn | 234 |
Back view of Zooman and Cohn | 240 |
Side view of Loewenthal and Morris | 258 |
Group of soldiers exercising in the Gymnasium | 262 |
Front view of Sliney | 272 |
Soldiers exercising in the Gymnasium | 284 |
Soldiers exercising in the Gymnasium | 296 |
Side view of Stapleton | 328 |
Back view of Stapleton | 366 |
Front view of W. L. Anderson and Bellis | 440 |
Back view of W. L. Anderson and Bellis | 442 |
The writer has been most generously aided by substantial grants from the Bache Fund of the National Academy of Sciences, and from the Carnegie Institution of Washington; also by large donations from Mr. Horace Fletcher of Venice, and from Mr. John H. Patterson of Dayton, Ohio. In addition, the War Department of the United States met in large measure the expense of maintaining at New Haven the Detachment of Volunteers from the Hospital Corps of the United States Army, detailed here through the courtesy of Surgeon-General Robert Maitland O’Reilly.
The successful carrying out of the experiments in all their details, especially the chemical work, has been rendered possible by the active and continuous co-operation of the writer’s colleague, Lafayette B. Mendel, Ph.D., Professor of Physiological Chemistry in the Sheffield Scientific School.
Efficient aid in the routine chemical and other work of the laboratory in connection with the experiments has been rendered by Frank P. Underhill, Ph.D., Arthur L. Dean, Ph.D., Harold C. Bradley, B.A., Robert B. Gibson, Ph.B., Oliver E. Closson, Ph.B., and Charles S. Leavenworth, Ph.B.
Dr. William G. Anderson, Director of the Yale Gymnasium, with the co-operation of his assistants, has rendered valuable aid in looking after the physical development of the men[vi] under experiment, in arranging for frequent strength tests, as well as in prescribing the character and extent of their work in the Gymnasium. The greater portion of the training of the soldiers was under the personal supervision of William H. Callahan, M.D., Medical Assistant at the Gymnasium, while Messrs. William Chase, Anton Muller, John Stapleton, and H. R. Gladwin, Assistant Instructors in the Gymnasium, led the drills and looked after the actual muscular training of the men.
In the study of “Reaction Time” and other matters of psychological interest the work was under the direction of Charles H. Judd, Ph.D., in charge of the Yale Psychological Laboratory, aided by Warren M. Steele, B.A., and Cloyd N. McAllister, Ph.D.
In the morphological study of the blood, etc., Dr. Wallace DeWitt, Lieutenant in command of the Army detail, rendered valuable aid. Dr. DeWitt likewise co-operated in all possible ways during his stay in New Haven to maintain the integrity of the conditions necessarily imposed on the soldier detail in an experiment of this character.
Further, acknowledgments are due the several non-commissioned officers of the Hospital Corps for their intelligent co-operation and interest. Finally, to the men of the Hospital Corps who volunteered for the experiment, our thanks are due for their cheerful compliance with the many restrictions placed upon them during their six months’ sojourn in New Haven, and for the manly way in which they conducted themselves under conditions not always agreeable.
To the students of the University who volunteered as subjects of experiment our acknowledgments are due for their intelligent co-operation, keen interest, and hearty compliance with the conditions imposed.
There is no subject of greater physiological importance, or of greater moment for the welfare of the human race, than the subject of nutrition. How best to maintain the body in a condition of health and strength, how to establish the highest degree of efficiency, both physical and mental, with the least expenditure of energy, are questions in nutrition that every enlightened person should know something of, and yet even the expert physiologist to-day is in an uncertain frame of mind as to what constitutes a proper dietary for different conditions of life and different degrees of activity. We hear on all sides widely divergent views regarding the needs of the body, as to the extent and character of the food requirements, contradictory statements as to the relative merits of animal and vegetable foods; indeed, there is great lack of agreement regarding many of the fundamental questions that constantly arise in any consideration of the nutrition of the human body. Especially is this true regarding the so-called dietary standards, or the food requirements of the healthy adult. Certain general standards have been more or less widely adopted, but a careful scrutiny of the conditions under which the data were collected leads to the conclusion that the standards in question have a very uncertain value, especially as we see many instances of people living, apparently in good physical condition, under a régime not at all in harmony with the existing standards.
Especially do we need more definite knowledge of the true physiological necessities of the body for proteid or albuminous foods, i. e., those forms of foods that we are accustomed to speak of as the essential foods, since they are absolutely requisite for life. If our ideas regarding the daily quantities of these foods necessary for the maintenance of health and[viii] strength are exaggerated, then a possible physiological economy is open to us, with the added possibility that health and vigor may be directly or indirectly increased. Further, if through years and generations of habit we have become addicted to the use of undue quantities of proteid foods, quantities way beyond the physiological requirements of the body, then we have to consider the possibility that this excess of daily food may be more or less responsible for many diseased conditions, which might be obviated by more careful observance of the true physiological needs of the body.
First, however, we must have more definite information as to what the real necessities of the body for proteid food are, and this information can be obtained only by careful scientific experimentation under varying conditions. This has been the object of the present study, and the results obtained are now placed before the public with the hope that they will prove not only of scientific interest and value, but that they will also serve to arouse an interest in the minds of thoughtful people in a subject which is surely of primary importance for the welfare of mankind. That the physical condition of the body exercises an all-powerful influence upon the mental state, and that a man’s moral nature even is influenced by his bodily condition are equally certain; hence, the subject of nutrition, when once it is fully understood and its precepts obeyed, bids fair to exert a beneficial influence not only upon bodily conditions, but likewise upon the welfare of mankind in many other directions.
In presenting the results of the experiments, herein described, the writer has refrained from entering into lengthy discussions, preferring to allow the results mainly to speak for themselves. They are certainly sufficiently convincing and need no superabundance of words to give them value; indeed, such merit as the book possesses is to be found in the large number of consecutive results, which admit of no contradiction and need no argument to enhance their value. The results presented are scientific facts, and the conclusions they justify are self-evident.
Page | |
Acknowledgments | v |
Preface | vii |
Introductory | 1 |
I. Experiments with Professional Men. |
|
Chittenden: Daily Record of Nitrogen Excretion, etc. | 24 |
First Nitrogen Balance, with comparison of income and output, amount and character of the daily food | 34 |
Second Nitrogen Balance, with composition of daily food, etc. | 43 |
Mendel: Daily Record of Nitrogen Excretion, etc. | 53 |
First Nitrogen Balance, with comparison of income and output, amount and character of the daily food | 60 |
Second Nitrogen Balance, with composition of daily food, etc. | 67 |
Underhill: Daily Record of Nitrogen Excretion, etc. | 79 |
First Nitrogen Balance, with comparison of income and output, composition of the daily food, etc. | 87 |
Second Nitrogen Balance, with composition of daily food, etc. | 93 |
Dean: Daily Record of Nitrogen Excretion, etc. | 98 |
Nitrogen Balance, with comparison of income and output, amount and character of the daily food | 103 |
Beers: Daily Record of Nitrogen Excretion, etc. | 111 |
First Nitrogen Balance, with comparison of income and output, amount and character of the daily food | 114 |
Second Nitrogen Balance, with composition of daily food, etc. | 121 |
Summary of Results; True Proteid Requirements | 127 |
II. Experiments with Volunteers from the Hospital Corps of the United States Army. |
|
Description of the Men | 134 |
Daily Routine of Work | 135[x] |
Daily Record of Nitrogen Excretion, etc., for each of the thirteen men under experiment | 139 |
Average Daily Output of Nitrogen | 199 |
Nitrogen Metabolized per kilo of Body-Weight | 201 |
Changes in Body-Weight during the Experiment | 202 |
First Nitrogen Balance, with comparison of income and output, amount and character of the daily food | 203 |
Second Nitrogen Balance, with composition of daily food, etc. | 223 |
Third Nitrogen Balance, with composition of daily food, etc. | 242 |
Summary regarding Nitrogen Requirement | 254 |
Physical Training of the Men—Report by Dr. Anderson of the Yale Gymnasium | 255 |
Body Measurements | 261 |
Strength or Dynamometer Tests | 262 |
Comparison of the Total Strength of the Men at the beginning and end of the Experiment | 274 |
Reaction Time Experiments—Report by Dr. Judd of the Yale Psychological Laboratory | 276 |
Character and Composition of the Blood | 283 |
General Conclusions | 285 |
Daily Dietary of the Soldier Detail | 288 |
III. Experiments with University Students, trained in Athletics. |
|
Consumption of Proteid Food by Athletes | 327 |
Description of the Men | 329 |
Daily Record of Nitrogen Excretion, etc., for each of the eight men under Experiment | 332 |
Average Daily Excretion of Metabolized Nitrogen | 364 |
Metabolized Nitrogen per kilo of Body-Weight | 365 |
Daily Diet Prescribed | 366 |
Nitrogen Balance, with comparison of income and output, and amount and character of the daily food, etc. | 375 |
The Physical Condition of the Men | 434 |
Strength or Dynamometer Tests | 436 |
Report by Dr. Anderson of the Yale Gymnasium | 439 |
Reaction Time—Report by Dr. Judd of the Yale Psychological Laboratory | 442 |
General Summary; True Physiological Requirements for Proteid Food | 454[xi] |
IV. The Systemic Value of Physiological Economy in Nutrition. |
|
Diseases due to Perversion of Nutrition | 455 |
Waste Products of Proteid Metabolism may be Dangerous to Health | 456 |
Origin and Significance of Uric Acid | 458 |
Modification of Uric Acid Excretion by diminishing the amount of Proteid Food | 463 |
Tables showing Excretion of Uric Acid by the three groups of men under observation; Uric Acid per kilo of Body-Weight, etc. | 467 |
V. | |
Economic and Sociological Importance of the Results | 471 |
VI. | |
General Conclusions | 474 |
VII. | |
Description of Illustrations | 477 |
Note.—For the benefit of lay readers, metabolism, a word frequently made use of, may be defined as a term applied to the collective chemical changes taking place in living matter. When these metabolic changes are constructive, as in the building up of tissue protoplasm from the absorbed food material, they are termed anabolic; when they are destructive, as in the breaking down of living matter or in the decomposition of the materials stored up in the tissues and organs, they are termed katabolic. Proteid metabolism, or more exactly proteid katabolism, therefore, means the destructive decomposition of proteid or albuminous matter in the living body and is practically synonymous with nitrogenous metabolism, since the entire nitrogen income is mainly supplied by the proteids or albuminous matters of the food. The chief carbon income, on the other hand, is supplied by fats and carbohydrates, such as starches and sugars.
As the result of many years of observation and experiment certain general conclusions have been arrived at regarding the requisite amounts of food necessary for the maintenance of health and strength. Certain dietary standards have been set up which have found more or less general acceptance in most parts of the civilized world; standards which have been reinforced and added to by man’s aptitude for self-indulgence. Carl Voit, of Munich, whose long and successful life as a student of Nutrition renders his conclusions of great value, considers that an adult man of average body-weight (70-75 kilos) doing moderate muscular work requires daily 118 grams of proteid or albuminous food, of which 105 grams should be absorbable, 56 grams of fat, and 500 grams of carbohydrate, with a total fuel value of over 3000 large calories, in order to maintain the body in equilibrium. The Voit standard or daily diet is accepted more or less generally as representing the needs of the body under normal conditions of life, and[2] the conclusions arrived at by other investigators along these same lines have been more or less in accord with Voit’s figures. In confirmation of this statement the following data may be quoted:
AVERAGE DIETS.
Moleschott. | Ranke.[1] | Forster. | Hultgren[2] and Landergren. | Atwater. | Studemund.[3] | Schmidt.[4] | |
---|---|---|---|---|---|---|---|
grams | grams | grams | grams | grams | grams | grams | |
Proteid | 130 | 100 | 131 | 134 | 125 | 114 | 105 |
Carbohydrates | 550 | 240 | 494 | 523 | 400 | 551 | 541 |
Fats | 40 | 100 | 68 | 79 | 125 | 54 | 63 |
Fuel value (calories)[5] | 3160 | 2324 | 3195 | 3436 | 3315 | 3229 | 3235 |
In many of these diets it is to be noted that the proteid requirement is placed at even a higher figure than Voit’s standard. Similarly, Erisman, studying the diets of Russian workmen having a free choice of food and doing moderately hard work, found the daily diet to be composed of 131.8 grams of proteid, 79.7 grams of fat, and 583.8 grams of carbohydrate, with a total fuel value of 3675 large calories. Further, Hultgren and Landergren[6] found that Swedish laborers doing hard work had as their daily diet 189 grams of proteid, 110 grams of fat, and 714 grams of carbohydrate, with a total fuel value of 4726 large calories. Voit found that German soldiers on active service consumed daily 145 grams of proteid, 100 grams of fat, and 500 grams of carbohydrate, with a total fuel value[3] of 3574 large calories. Lichtenfelt,[7] studying the nutrition of Italians, states that an Italian laborer doing a moderate amount of work requires 110.5 grams of proteid and a total fuel value for the daily food of 2698 calories, while at hard labor he needs 146 grams of proteid daily, with carbohydrates and fat sufficient to give 3088 large calories. In our own country Atwater,[8] who has made many valuable observations upon the dietetic habits of different classes of people and under different conditions of life, has stated that a somewhat more liberal allowance of proteid would seem desirable, say 125 grams, with a total fuel value of 3500 large calories for a man doing severe muscular labor.
In what is perhaps the latest book on alimentation, Armand Gautier,[9] writing of the French people, states that the ordinary man in that climate needs daily 110 grams of albuminous food, 68 grams of fat, and about 423 grams of amylaceous or saccharine food. It is possible, however, says Gautier, that the quantity of albuminous food can be reduced, if necessary, to 78 grams per day in case a man is not doing work and takes in addition at least 50 grams of fat and 485 grams of carbohydrate food. Where, however, an individual works eight to ten hours a day, the ration, says Gautier, must be increased to at least 135 grams of albuminous food, with 85 to 100 grams of fat, and with from 500 to 900 grams of starchy food.
While these figures may be taken as showing quite conclusively the dietetic standards adopted by mankind, there is no evidence whatever that they represent the real needs or requirements of the body. We may even question whether simple observation of the kinds and amounts of food consumed by different classes of people under different conditions of life have any very important bearing upon this question. They[4] throw light upon dietetic habits, it is true, but such observations give no information as to how far the diets in question serve the real needs of the body. We may find, for example, that under certain given conditions of diet the people in question have the appearance of being well nourished, and that they do their work with apparent ease and comfort; but might not these same results follow with smaller amounts of food? If so, there must of necessity be a certain amount of physiological economy under the more restricted diet, and a consequent ultimate gain to the body through diminished wear and tear of the bodily machinery.
Indeed, experimental work and observations scattered through the last few years have suggested the possibility of much lower standards of diet sufficing to meet the real physiological needs of the body. Thus, Hirschfeld,[10] in 1887, found in experimenting on himself (24 years of age and weighing 73 kilos) that it was possible to maintain nitrogen equilibrium on a diet containing only 5 to 7.5 grams of nitrogen per day, or 35 to 45 grams of proteid, for a period of ten to fifteen days. The amount of non-nitrogenous food consumed, however, was fairly large, especially the amount of butter,—frequently 100 grams a day—the average fuel value ranging from 3750 to 3916 large calories daily. In 1888 Hirschfeld,[11] again experimenting on himself, maintained nitrogen equilibrium for several days on 7.5 grams of nitrogen per day, with fats and carbohydrate sufficient to yield a total fuel value of 3462 large calories as the daily average. The chief criticism of Hirschfeld’s experiments is that he failed to obtain in all cases definite analytical data of the food-stuffs employed and failed to determine the nitrogen of the fæces. Still his results are of value as indicating the possibility of maintaining nitrogenous equilibrium for a brief time at least on a low proteid intake.
Kumagawa,[12] studying especially the diet of the Japanese and experimenting on himself (27 years old and weighing 48 kilos), found with a purely vegetable diet, containing per day 54.7 grams of proteid, 2.5 grams of fat, and 569.8 grams of carbohydrate, that he showed for a period of nine days a plus balance of nitrogen, indicating that his body was laying on about 4 grams of proteid per day. The nitrogen excreted per urine and fæces amounted to 8.09 grams per day, while the nitrogen in the daily food amounted to 8.75 grams. It is interesting to observe in these experiments, as indicating the degree of absorption of the vegetable food (composed in large measure of rice) that the daily average of nitrogen in the urine amounted to 6.069 grams and in the fæces 2.029 grams. In other words, of the 54.7 grams of nitrogen-containing food only 37.8 grams were absorbed, 12.69 grams passing out with the fæces. The total fuel value of the absorbed food per day was 2478 large calories. Similarly, Hirschfeld[13] has called attention to the fact that with many vegetable foods especially, not more than 75 per cent of the ingested proteid can be digested and absorbed, thus emphasizing the necessity of paying heed to the character of the proteid food in considering the nutritive value of a given diet.
In some experiments reported by C. Voit[14] in 1889, on the diet of vegetarians, E. Voit and Constantinidi found that nitrogenous equilibrium was established in one man with about 8 grams of nitrogen, corresponding to 48.5 grams of proteid as the daily diet, with large amounts of starchy foods and some fat. Similarly, Nakahama[15] in the same year, studying the diet (mostly vegetable) and nutritive condition of thirteen German laborers in Leipzig, found that their daily[6] food contained on an average 85 grams of proteid, but Carl Voit criticising these results states that the men were of comparatively light body-weight—about 60 kilos—and not well nourished.
Kellner and Mori,[16] studying the nutrition of a Japanese (weighing 52 kilos and 23 years of age) state that on a purely vegetable diet containing 11.34 grams of nitrogen, of which only 8.58 grams were digested, there was a distinct loss of body-weight, with a daily loss to the body of 1.16 grams of nitrogen. On a mixed diet, however, containing fish, it was possible to establish nitrogenous equilibrium with a daily diet containing 17.48 grams of nitrogen, of which 15.27 grams were digested and utilized. Similarly, Caspari,[17] 29 years old and weighing 66.2 kilos, found that while he could maintain his body in nitrogenous equilibrium on 13.26 grams of nitrogen per day, he could not accomplish it on 10.1 grams of nitrogen, though his daily food contained 3200 large calories.
Other investigators, however, have found no great difficulty in establishing nitrogenous equilibrium in man with much lower quantities of proteid food. Thus, Klemperer[18] found in the case of two young men of 64 and 65.5 kilos body-weight respectively, in an experiment lasting eight days, that nitrogenous equilibrium was established on 4.38 and 3.58 grams of nitrogen per day, but with a daily diet containing in addition to the small amount of proteid 264 grams of fat, 470.4 grams of carbohydrate, and 172 grams of alcohol, with a total fuel value of 5020 large calories.
Peschel,[19] too, has reported experimental results showing that he was able to establish nitrogenous equilibrium for a[7] brief period with 7 grams of nitrogen daily, 5.31 grams appearing in the urine and 1.58 grams in the fæces.
Caspari and Glaessner,[20] in a five-days’ experiment with two vegetarians, found that the wife consumed daily, on an average, 5.33 grams of nitrogen, with fats and carbohydrates to equal 2715 calories, while the man took in 7.82 grams of nitrogen and 4559 calories. Both persons laid on nitrogen in spite of the low intake of proteid food.
Siven’s[21] experiments, however, are perhaps worthy of more careful consideration. Of 60 kilos body-weight and 30½ years of age, his experiments conducted on himself extended through thirty-two days with establishment of nitrogenous equilibrium on 6.26 grams of nitrogen. Moreover, in another experiment he was in nitrogen equilibrium for a day or two at least on 4.5 grams of nitrogen. In Siven’s experiment, the most noticeable feature is the added fact that the total intake of food per day was comparatively low, with a fuel value of only 2444 large calories. In this connection we may call attention to the recent experiments of Landergren,[22] who found with four individuals fed on a daily diet containing only 2.1 to 2.4 grams of nitrogen, but with a large amount of carbohydrate, some fat and alcohol, that on the fourth day of this “specific nitrogen hunger” only 3 to 4 grams of nitrogen were metabolized and appeared in the urine. In other words, a healthy adult man having a sufficient intake of non-nitrogenous food seemingly need not metabolize more proteid than suffices to yield 3 to 4 grams of nitrogen per day.
Such data as these, of which many more might be quoted, surely warrant the question, how far are we justified in assuming the necessity for the rich proteid diet called for by the Voit standard? Voit, however, with many other physiologists[8] would apparently object to any diminution of the daily 118 grams of proteid for the moderate worker, on the ground that an abundance of proteid in the food is a necessity for the maintenance of physical vigor and muscular activity. This view is certainly reinforced by the customs and habits of mankind; but we may well query whether our dietetic habits will bear criticism, and in the light of modern scientific inquiry we may even express doubt as to whether a rich proteid diet adds anything to our muscular energy or bodily strength.
How far can our natural instinct be trusted in the choice of diet? We are all creatures of habit, and our palates are pleasantly excited by the rich animal foods with their high content of proteid, and we may well question whether our dietetic habits are not based more upon the dictates of our palates than upon scientific reasoning or true physiological needs. There is a prevalent opinion that to be well nourished the body must have a large excess of fat deposited throughout the tissues, and that all bodily ills and weaknesses are to be met and combated by increased intake of food. There is constant temptation to increase the daily ration, and there is almost universal belief in the efficacy of a rich and abundant diet to strengthen the body and to increase bodily and mental vigor. Is there any justification for these beliefs? None, apparently, other than that which comes from the customs of generations of high living.
It is self-evident that the smallest amount of food that will serve to keep the body in a state of high efficiency is physiologically the most economical, and hence the best adapted for the needs of the organism. Any excess over and above what is really needed is not only uneconomical, but may be directly injurious. This is especially true of the proteid or albuminous foods. It is, however, quite proper to question whether a brief experiment of a few days in which nitrogenous equilibrium is perhaps established at the low level of 4 to 5 grams of nitrogen, the equivalent of 25 to 35 grams of proteid, is to be accepted as fixing the daily requirements of the healthy man, offsetting the customs or habits of a lifetime. Voit himself,[9] however, has clearly emphasized the general principle that the smallest amount of proteid, with non-nitrogenous food added, that will suffice to keep the body in a state of continual vigor is the ideal diet. Proteid decomposition products are a constant menace to the well-being of the body; any quantity of proteid or albuminous food beyond the real requirements of the body may prove distinctly injurious. We see the evil effects of uric acid in gout, but there are many other nitrogenous waste products of proteid katabolism, which with excess of proteid food are liable to be unduly conspicuous in the fluids and tissues of the body, and may do more or less damage prior to their excretion through the kidneys. Further, it requires no imagination to understand the constant strain upon the liver and kidneys, to say nothing of possible influence upon the central and peripheral parts of the nervous system, by these nitrogenous waste products which the body ordinarily gets rid of as speedily as possible. They are an ever present evil, but why increase them unnecessarily? This question brings us back to the starting-point. What is the minimal proteid requirement for the healthy man, or rather, how far can we safely and advantageously diminish our proteid intake below the commonly accepted standards?
The question of safety is a pertinent one. Thus, Munk[23] some years ago (1893) sounded a warning on this point which was later confirmed by Rosenheim.[24] Both of these observers reported that in dogs fed for some time on a low proteid diet, but with an abundance of carbohydrate and fat, there was after some weeks (6-8) a loss of the power of absorption from the alimentary tract, dependent not alone upon a changed condition of the epithelial cells of the intestine, but also upon a diminished secretion of the digestive juices, loss of body-weight, strength, and vigor, followed speedily by death. If[10] these results were really due to the low proteid diet, they suggest a grave danger which must not be lightly passed by. Jägerroos[25] has likewise observed, experimenting on dogs, that there was, after some months, a striking disturbance of the intestines on a low proteid intake, which, however, was eventually traced to a distinct infection, and probably in no manner connected with the diminished amount of proteid in the diet. In these various experiments on dogs carried out by Munk, Rosenheim, and by Jägerroos, there was of necessity great monotony in the diet, and in Munk’s experiments no fresh meat at all was fed, but simply dried food. In other words, if the diet was in any sense responsible for the poor health of the animals, it is fully as plausible to attribute the results to the abnormal conditions under which the animals were kept as to any specific effect due to the low proteid intake. It is very essential that the food of dogs, as of men, shall fulfil all ordinary hygienic conditions. It must be not only of sufficient quantity for the true needs of the body, but it should also have the necessary variety with reasonable degree of digestibility, and proper volume or bulk. When these qualities are lacking, it is not strange if deviations from the normal gradually develop. That the low intake of proteid food could be responsible for the condition existing in Munk’s and Rosenheim’s experiments is not plausible; a view which is strongly reinforced by many observations, notably those of Albu[26] on a woman thirty-seven years old and weighing 37.5 kilos, who had followed a vegetarian diet for six years, and who while under Albu’s care for two years consumed only 34 grams of proteid per day, the total fuel value of the food being only 1400 calories per day. This woman was in nitrogenous equilibrium on 5.4 grams of nitrogen, and on this diet had freed herself from the illness to which she had long been subject.
Voit’s[27] vegetarian is described by Voit himself as a man twenty-eight years old, weighing 57 kilos, well nourished, with well developed muscles, etc. He had lived on a purely vegetable diet for three years, and was found to be in nitrogenous equilibrium on 8.2 grams of nitrogen. No mention is made of any disagreeable effects connected with this low proteid ration, although persisted in for several years. Jaffa’s[28] experiments and observations on the fruitarians and nutarians of California “showed in every case (two women and three children) that though the diet had a low protein and energy value, the subjects were apparently in excellent health and had been so during the five to eight years they had been living in this manner.” In comparing the income and outgo of nitrogen on a diet composed mainly of nuts and fruits, it was observed in two subjects that 8 grams of nitrogen were sufficient to bring about nitrogen equilibrium, while with two other subjects on a like diet the nitrogen required daily for equilibrium was about 10 grams. The diet used in these experiments, however, was of necessity more or less restricted in variety, and was without doubt somewhat monotonous. Jaffa appears to agree with Caspari that the minimum amount of proteid required daily varies with the individual, and may even vary with the same individual at different times. Further, Jaffa, in harmony with Siven, believes that after the body has suffered a loss of nitrogen, there is at once an effort to attain nitrogenous equilibrium, and that any gain of nitrogenous body material is a comparatively slow process. If this is true, it is obvious that the living substance of the tissue protoplasm must be slowly formed from the proteid of the diet. This, says Jaffa, should serve as a warning to anyone contemplating any appreciable decrease in the proteid of the daily diet.
Another statement made by Jaffa may be quoted in this[12] connection, since it illustrates the attitude taken by many physiologists on this question. “Even if it could be proved,” says Jaffa, “by a large number of experiments that nitrogen equilibrium can be maintained on a small amount of protein, it would still be a great question whether or not it would be wise to do so. There must certainly be a constant effort on the part of the human organism to attain this condition, and with a low protein supply it might be forced to do so under conditions of strain. In such a case the bad results might be slow in manifesting themselves, but might also be serious and lasting. It has also been suggested that when living at a fairly high protein level the body is more resistant to disease and other strains than when the protein level is low.” While these suggestions demand careful consideration, it is equally evident that there is another side to the question, viz., the possible danger to the body from the physiological action of the larger amounts of nitrogenous waste products which result from an excess of proteid food, and which float about through the system prior to their excretion. In addition, we must not overlook the great loss of energy to the body in handling and getting rid of the surplus of unnecessary food of whatever kind introduced into the alimentary tract, to say nothing of the danger of intestinal putrefaction and toxæmia when from any cause the system loses its ability to digest and absorb the excess of food consumed. Further, the possible strain on the kidneys and other organs must not be overlooked. Hence we may well query on which side lies the greater danger. To an unprejudiced observer, one not wedded to old-time tradition, it would seem as if great effort was being made to sustain the claims of a high-proteid intake. It is surely well to be careful, but it is certainly not necessary to magnify imaginary dangers to the extent of suppressing all efforts toward the establishment of possible physiological economy.
In a paper read before the Physiological Section of the British Medical Association in 1901 by Dr. van Someren, claim is made of the existence of a reflex of deglutition, the proper working of which protects from the results of malnutrition[13] by preventing the intake of any excess of food. Thorough mastication and insalivation aid in the more complete utilization of the food and render possible great economy, so that body-weight and nitrogen equilibrium are both maintained on an exceptionally small amount of food. This principle had been worked out by Mr. Horace Fletcher on himself in an attempt to restore his health to a normal condition, with such beneficial results that he was speedily restored to a state of exceptional vigor and well-being. Deliberation in eating, necessitated by the habit of thorough insalivation, it is claimed results in the occurrence of satiety on the ingestion of comparatively small amounts of food, and hence all excess of food is avoided.
In the autumn of 1901, Mr. Fletcher and Dr. van Someren visited the physiological laboratories of Cambridge University, and as stated by Sir Michael Foster[29] the matter was more closely inquired into with the assistance of physiological experts. Observations were carried out on various individuals, and as stated by Professor Foster “the adoption of the habit of thorough insalivation of the food was found in a consensus of opinion to have an immediate and very striking effect upon appetite, making this more discriminating, and leading to the choice of a simple dietary, and in particular reducing the craving for flesh food. The appetite, too, is beyond all question fully satisfied with a dietary considerably less in amount than with ordinary habits is demanded.”... “In two individuals who pushed the method to its limits it was found that complete bodily efficiency was maintained for some weeks upon a dietary which had a total energy value of less than one-half of that usually taken, and comprised little more than one-third of the proteid consumed by the average man.” Finally, says Foster, “it may be doubted if continued efficiency could be maintained with such low values as these, and very prolonged observations would be necessary to establish the facts. But all subjects of the experiments who applied the principles[14] intelligently agreed in finding a very marked reduction in their needs, and experienced an increase in their sense of well-being and an increase in their working powers.”
In the autumn of 1902 and in the early part of 1903, Mr. Fletcher spent several months with the writer, thereby giving an opportunity for studying his habits of life. For a period of thirteen days in January he was under constant observation in the writer’s laboratory, when it was found that the average daily amount of proteid metabolised was 41.25 grams, his body-weight (75 kilos) remaining practically constant. Later, a more thorough series of observations was made, involving a careful analysis of the daily diet, together with analysis of the excreta. For a period of six days the daily diet averaged 44.9 grams of proteid, 38.0 grams of fat, and 253 grams of carbohydrate, the total fuel value amounting to only 1606 large calories per day. The daily intake of nitrogen averaged 7.19 grams, while the daily output through the urine was 6.30 grams and in the fæces 0.6 gram; i. e., a daily intake of 7.19 grams of nitrogen, with a total output of 6.90 grams, showing a daily gain to the body of 0.29 gram of nitrogen, and this on a diet containing less than half the proteid required by the Voit standard and having only half the fuel value of the Voit diet. Further, it was found by careful and thorough tests made at the Yale Gymnasium that Mr. Fletcher, in spite of this comparatively low ration was in prime physical condition. In the words of Dr. Anderson, the Director of the Gymnasium, “the case is unusual, and I am surprised that Mr. Fletcher can do the work of trained athletes and not give marked evidences of over-exertion.... Mr. Fletcher performs this work with greater ease and with fewer noticeable bad results than any man of his age and condition I have ever worked with.”[30] It is not our purpose here to discuss how far these results are due to insalivation, or the more thorough mastication of food. The main point for us is that we have here a striking illustration of the establishment of nitrogen[15] equilibrium on a low proteid diet and great physiological economy as shown by the low fuel value of the food consumed, coupled with remarkable physical strength and endurance.
With data such as these before us we see the possible importance of a fuller and more exact knowledge of true dietary standards. We find here questions suggested, the answers to which are of primary importance in our understanding of the nutritive processes of the body; greater ease in the maintenance of health, increased power of resistance to disease germs, duration of life increased beyond the present average, greater physiological economy and greater efficiency, increased mental and physical vigor with less expenditure of energy on the part of the body. All these questions rise before us in connection with the possibility of maintaining equilibrium on a lowered intake of food, especially nitrogenous equilibrium, with a diminished consumption of proteid or albuminous food. Is it not possible that the accepted dietary standards are altogether too high?
It is of course understood that there can be no fixed dietary standard suitable for all people, ages, and conditions of life. Dietary standards at the best are merely an approximate indication of the amounts of food needed by the body, but these needs are obviously changeable, varying with the degree of activity of the body, especially the amount of physical work performed, to say nothing of differences in body-weight, sex, etc. Further, it is doubtless true that there is what may be called a specific coefficient of nutrition characteristic of the individual, a kind of personal idiosyncrasy which exercises in some degree a modifying influence upon the character and extent of the changes going on in the body. Still, with due recognition of the general influence exerted by these various factors the main question remains, viz., how far the usually accepted standards of diet are correct; or, in other words, is there any real scientific ground for the assumption that the average individual doing an average amount of work requires any such quantity of proteid, or of total nutrients, as the ordinary dietetic standards call for? Cannot all the real physiological[16] needs of the body be met by a greatly reduced proteid intake, with establishment of continued nitrogenous equilibrium on a far smaller amount of proteid food than the ordinary dietary standards call for, and with actual gain to the body?
Just here we may emphasize why prominence is given to the establishment of nitrogenous equilibrium, and why the proteid intake assumes a greater importance than the daily amounts of fat and carbohydrate consumed. Fats and carbohydrates when oxidized in the body are ultimately burned to simple gaseous products, viz., carbonic acid and water. Hence, these waste products are easily and quickly eliminated and cannot exercise much deleterious influence even when formed in excess. To be sure, there is waste of energy in digesting, absorbing, and oxidizing the fats and carbohydrates when they are taken in excessive amounts. Once introduced into the alimentary canal they must be digested, otherwise they will clog the intestine or undergo fermentation, and so cause trouble. Further, when absorbed they may be transformed into fat and deposited in the various tissues and organs of the body; a process desirable up to a certain point, but undesirable when such accumulation renders the body gross and unwieldy. With proteid foods, on the other hand, the story is quite different. These substances, when oxidized, yield a row of crystalline nitrogenous products which ultimately pass out of the body through the kidneys. Prior to their excretion, however, these products—frequently spoken of as toxins—float about through the body and may exercise more or less of a deleterious influence upon the system, or, being temporarily deposited, may exert some specific or local influence that calls for their speedy removal. Hence, the importance of restricting the production of these bodies to the minimal amount, owing to their possible physiological effect and the part they are liable to play in the causation of many diseased conditions. Further, the elimination of excessive amounts of these crystalline nitrogenous bodies through the kidneys places upon these organs an unnecessary burden which[17] is liable to endanger their integrity and possibly result in serious injury, to say nothing of an early impairment of function.
The present experiments were undertaken to throw light upon this broad question of a possible physiological economy in nutrition, and with special reference to the minimal proteid requirement of the healthy man under ordinary conditions of life. The writer as a student of physiology has always maintained that man is disposed to eat far more than the needs of the body require, but his active interest in this problem was aroused especially by his observations of Mr. Fletcher and the marked physiological economy the latter was able to practice, not only without detriment, but apparently with great gain to the body as regards strength, vigor, and endurance, coupled with an apparent resistance to disease. While Mr. Fletcher and Dr. Van Someren would doubtless emphasize the importance of insalivation as a means of controlling the appetite and thereby regulating the consumption of food in harmony with the real needs of the body, it is of primary importance for the physiologist and for mankind to know definitely how far it is possible to reduce the intake of food with perfect safety and without loss of that strength, mental and physical, vigor, and endurance which are characteristic of good health. Further, it is equally plain that if there is possible gain to the body from a practice of physiological economy in diet, we should know how far this can be accomplished by simple restriction in the amount of food without complicating the problem by other factors.
In planning the conduct of this series of experiments the writer has clearly recognized that, while it may be possible, as previous experiments have shown, to maintain body equilibrium and nitrogen equilibrium on a low proteid diet for a brief period, this fact does not, as Munk has previously pointed out, by any means establish the view that such a diet will prove efficient in maintaining equilibrium for a long period, or that bodily strength and vigor can be kept up and the proper resistance to disease secured. Hence, it seemed[18] necessary to so arrange the experiments that they should continue not for a few days or weeks merely, but through months and years. Further, it is very questionable whether the restricted diet (restricted in variety) frequently made use of for convenience in ordinary metabolism experiments is well adapted for bringing out the best results. Hence, it was decided to avoid so far as possible any monotony of diet, giving due recognition to the psychical influences liable to affect secretion, digestion, etc., so admirably worked out by Pawlow in his classical experiments on these subjects; influences which are unquestionably of great importance in controlling and modifying, in some measure at least, the nutritive changes in the body. Again, it is evident that to have experiments of this character broadly useful, they must be tried upon a large number of people and under different conditions of life, in order to avoid so far as possible the influence of personal idiosyncrasy and thereby escape misleading conclusions.
The experiments have been conducted with three distinct types or classes of individuals:
1st. A group of five men of varying ages, connected with the University as professors and instructors; men who while leading active lives have not engaged in very active muscular work. They were selected as representatives of the mental worker rather than the physical worker, although several of them in the performance of their daily duties had to be on their feet in the laboratory a good portion of the day.
2d. A detail of thirteen men, volunteers from the Hospital Corps of the United States Army and representatives of the moderate worker; men who for a period of six months took each week day a vigorous amount of systematic exercise in the gymnasium, in addition to the routine work connected with their daily life as members of the United States Hospital Corps. These men were of different nationalities, ages, and temperaments.
3d. A group of eight young men, students in the University, all thoroughly trained athletes, and some of them with exceptional records in athletic events.
Before proceeding with a detailed account of the experimental work, it may be well again to emphasize that what is especially desired is to ascertain how far, if any, the intake of proteid food can be diminished without detriment to the body, i. e., with maintenance of nitrogen and body equilibrium and without impairment of bodily and mental vigor. Further, if a lower proteid standard than that generally adopted can be established, it is desirable to ascertain whether it can be maintained indefinitely, or for a long period of time, without loss of strength and vigor. Obviously, it is of primary importance that we should know quite definitely what the minimal proteid requirement of the healthy man per kilo of body-weight really is, and the experimental work about to be detailed has aimed especially to determine whether it is possible to materially lower the amount of daily proteid food, without detriment to the bodily health and with maintenance of physical and mental vigor.
The writer, fully impressed with his responsibility in the conduct of an experiment of this kind, began with himself in November, 1902. At that time he weighed 65 kilos, was nearly 47 years of age, and accustomed to eating daily an amount of food approximately equal to the so-called dietary standards. Recognizing that the habits of a lifetime should not be too suddenly changed, a gradual reduction was made in the amount of proteid or albuminous food taken each day. In the writer’s case, this resulted in the course of a month or two in the complete abolition of breakfast, except for a small cup of coffee. A light lunch was taken at 1.30 P. M., followed by a heavier dinner at 6.30 P. M. Occasionally, however, the heartier meal was taken at noontime, as the appetite suggested. It should be added that the total intake of food was gradually diminished, as well as the proteid constituents. There was no change, however, to a vegetable diet, but a simple introduction of physiological economy. Still, there was and is now a distinct tendency toward the exclusion of meat in some measure,[20] the appetite not calling for this form of food in the same degree as formerly. At first, this change to a smaller amount of food daily was attended with some discomfort, but this soon passed away, and the writer’s interest in the subject was augmented by the discovery that he was unquestionably in improved physical condition. A rheumatic trouble in the knee joint, which had persisted for a year and a half and which only partially responded to treatment, entirely disappeared (and has never recurred since). Minor troubles, such as “sick headaches” and bilious attacks, no longer appeared periodically as before. There was greater appreciation of such food as was eaten; a keener appetite and a more acute taste seemed to be developed, with a more thorough liking for simple foods. By June, 1903, the body-weight had fallen to 58 kilos.
During the summer the same simple diet was persisted in—a small cup of coffee for breakfast, a fairly substantial dinner at midday and a light supper at night. Two months were spent in Maine at an inland fishing resort, and during a part of this time a guide was dispensed with and the boat rowed by the writer frequently six to ten miles in a forenoon, sometimes against head winds (without breakfast), and with much greater freedom from fatigue and muscular soreness than in previous years on a fuller dietary. The test of endurance and fitness for physical work which the writer thus carried out “on an empty stomach” tended to strengthen the opinion that it is a mistake to assume the necessity for a hearty meal because heavy work is about to be done. It is certainly far more rational from a physiological standpoint to leave the hearty meal until the day’s work is accomplished. We seemingly forget that the energy of muscular contraction comes not from the food-stuffs present at the time in the stomach and intestinal tract, but rather from the absorbed material stored up in the muscles and which was digested and absorbed a day or two before. Further, it is to be remembered that the very process of digestion draws to the gastro-intestinal tract a large supply of blood, and that a large amount of energy is needed for the processes of secretion, digestion, absorption, and[21] peristalsis, which are of necessity incited by the presence of food in the stomach and intestine, thereby actually diminishing the amount of energy available at the place where it is most needed. Why, then, draw upon the resources of the body just at a time, or slightly prior to the time, when the work we desire to perform, either muscular or mental, calls for a copious blood supply in muscle or brain, and when all available energy is needed for the task that is to be accomplished?
We are too wont to compare the working body with a machine, the boiler, engine, etc., overlooking the fact that the animal mechanism differs from the machine in at least one important respect. When we desire to set machinery in operation we must get up steam, and so a fire is started under the boiler and steam is generated in proportion as fuel is burned. The source of the energy made use of in moving the machinery is the extraneous combustible material introduced into the fire-box, but the energy of muscular contraction, for example, comes not from the oxidizable food material in the stomach, but from the material of the muscle itself. In other words, in the animal body it is a part of the tissue framework, or material that is closely incorporated with the framework, that is burned up, and the ability to endure continued muscular strain depends upon the nutritive condition of the muscles involved, and not upon the amount of food contained in, or introduced into, the stomach. All physiologists will, I think, acknowledge the soundness of this reasoning, but how few of us apply the principle in practice. It is perfectly logical to begin the work of the day with a comparatively empty stomach,—after we have once freed ourselves from the habit of a hearty breakfast,—and in the writer’s experience both mental and physical work have become the easier from this change of habit. The muscle and the brain are given opportunity to repair the waste they have undergone, by the taking of food at times when the digestive processes will not draw upon the energy that in activity is needed elsewhere.
Further, it is easy to understand why on a restricted diet, especially of proteid foods, there should be a diminished sense[22] of fatigue in connection with vigorous or continued muscular work, and why at the same time there should be an increased power of endurance, with actual increase of strength. With a diminished intake of proteid food there is a decreased formation of crystalline nitrogenous waste products, such as uric acid and the purin bases, to say nothing of other bodies less fully known, which circulating through the system are undoubtedly responsible, in part at least, for what we term fatigue. We need not consider here whether the sense of fatigue is due to an action of these substances upon the muscles themselves, upon the motor nerves or their end-plates, or upon the central nervous system; it is enough for the present purpose to emphasize the probable results of their presence in undue amount. Lastly, we may emphasize what is pretty clearly evident to-day, viz., that the energy of muscular contraction comes preferably from the oxidation, not of the nitrogenous or proteid constituents of the muscles, but of the non-nitrogenous components of the tissue; another reason why excess of proteid food may be advantageously avoided. Moreover, proteid food stimulates body metabolism in general, and hence undue amounts of proteid in the diet augment unnecessarily the metabolism or combustion of the non-nitrogenous material of the muscle, thereby destroying what would otherwise be preserved as a source of energy in muscular contraction, when the muscles are called upon for the performance of their daily functions.
On the writer’s return to New Haven in the fall of 1903, he was surprised to find that his body-weight was practically the same as early in July. In the period between November, 1902, and July, 1903, the body had lost 8 kilos under the gradual change of diet, but from July to October, 1903, the weight had apparently remained stationary, from which it might fairly be assumed that the body had finally adjusted itself to the new conditions.
What now was the condition of the body as regards nitrogen metabolism? To answer this question the entire twenty-four hours’ urine was collected practically every day, from[23] October 13, 1903, to June 28, 1904, representing a period of nearly nine months. This daily output through the kidneys was analyzed each day with special reference to the total nitrogen,[31] as a measure of the amount of proteid material metabolized. Total volume of the urine, specific gravity, uric acid, phosphoric acid, indican, and other points were also considered, the more important results being indicated in the following tables.
Scrutiny of the tables shows that during this period of nine months the body-weight was practically constant. The daily volume of urine was exceptionally small and fairly regular in amount, the average daily output for the nine months being 468 c.c. It is a noticeable fact that with a diminished intake of proteid food there is far less thirst, and consequently a greatly decreased demand for water or other fluids. Further, in view of the small nitrogenous waste there is no need on the part of the body for any large amount of fluid to flush out the kidneys. The writer has not had a turbid urine during the nine months’ period. With heavier eating of nitrogenous foods, an abundant water supply is a necessity to prevent the kidneys from becoming clogged, thereby explaining the frequent beneficial results of the copious libations of mineral[31] waters, spring waters, etc., frequently called for after, or with, heavy eating. Obviously, a small volume of urine each day means so much less wear and tear of the delicate mechanism of the kidneys. Somewhat noticeable, in a general way, is the apparent relationship between the volume of the urine and the nitrogen output, in harmony with the well-known diuretic action of urea. The specific gravity of the urine shows variation only within narrow limits, the daily average for the nine months being 1027.
Uric acid is noticeably small in quantity, the average daily output for the nine months’ period, based upon the determinations made, being only 0.392 gram.
Chief interest, however, centres around the figures for total nitrogen, since these figures give for each day the extent of the proteid metabolism; i. e., the amount of proteid material broken down in the body each day in connection with the wear and tear of the bodily machinery. To fully grasp the significance of these data, it should be remembered that the prevalent dietary standards are based upon the assumption that the average adult must metabolize each day at least 16 grams of nitrogen. Indeed, that is what actual analysis of the urine indicates in most cases. If now we look carefully through the figures shown in the above tables, covering a period from October 13, 1903, to June 28, 1904, it is seen that the daily nitrogen excretion is far different from 16 grams. Indeed, the figures for nitrogen are exceedingly low, and, moreover, they vary little from day to day. The average daily output of nitrogen through the urine for the entire period of nearly nine months is only 5.699 grams.
For the first six months the average daily excretion amounted to 5.82 grams of nitrogen, while from April 12 to June 28 the average daily excretion of nitrogen was 5.40 grams, thus showing a slight tendency downward. On the whole, however, there is shown a somewhat remarkable uniformity in the daily excretion. Thus, the average daily excretion for the month of November was 5.79 grams of nitrogen, for the month of March 5.66 grams, thus showing very little[32] difference in the output of nitrogen through the kidneys in these two periods, three months apart. In other words, the extent of proteid katabolism was essentially the same throughout the entire nine months, implying that the amount of proteid food eaten must have been fairly constant, and that the body had adapted itself to this new level of nutrition from which there was no tendency to deviate. There was no weighing out of food and no attempt to follow any specified diet. The greatest possible variety of simple foods was indulged in, and the dictates of the appetite were followed with the single precaution that excess was avoided. In other words, it was temperance in diet, and not prohibition. Yet it is equally true, in the writer’s case at least, that the appetite itself unconsciously served as a regulator, since there was, as a rule, no necessity to hold the appetite in check to avoid excess. Doubtless, the writer’s knowledge of the general composition of food-stuffs has had some influence in the choice of foods, and thereby aided in bringing about this somewhat remarkable uniformity in the daily output of nitrogen for such a long period of time on an unrestricted diet.
What now do the nitrogen figures show regarding the amount of proteid material metabolized each day? It will be remembered that the Voit standard calls for 118 grams of proteid or albuminous food daily, of which 105 grams should be absorbable, in order to maintain the body in a condition of nitrogen equilibrium, and in a state of physical vigor and general tone. This would mean a daily excretion through the urine of at least 16 grams of nitrogen. The daily output of nitrogen in the case under discussion, however, was 5.699 grams for a period of nearly nine months. This amount of nitrogen excreted through the urine means only 35.6 grams of proteid metabolized, or about one-third the amount called for by the Voit standard, or the standards generally adopted as expressing man’s daily requirement of proteid food. But was the body in nitrogenous equilibrium on this small amount of proteid food? Naturally, this question might be answered in the affirmative, on the basis of the constancy in body-weight[33] for the period from October to June, but more decisive proof is needed. The question was therefore settled by a careful comparison of the income and output, in which all the food eaten was carefully weighed and analyzed, while the nitrogen of the urine and fæces was determined with equal accuracy. The first experiment of this character to be quoted is for the week commencing March 20, a period of six days.
Following are the diets made use of each day, the weights of the various food-stuffs being given in grams. Likewise is shown the nitrogen content of the several food-stuffs for each day, and also a comparison of the nitrogen intake with the output of nitrogen through the urine:
Sunday, March 20, 1904.
Breakfast, 7.45 A. M.—One cup coffee, i. e., coffee 137.5 grams, cream 30.5 grams, sugar 9 grams.
Dinner, 1.30 P. M.—Stewed chicken 50 grams, mashed potato 131 grams, biscuit 49 grams, butter 13 grams, chocolate pudding 106 grams, one small cup coffee, i. e., coffee 64 grams, sugar 12 grams, cheese crackers 29 grams.
Supper, 6.30 P. M.—Lettuce sandwiches 56 grams, biscuit 35 grams, butter 6 grams, one cup tea, i. e., tea 170 grams, sugar 7 grams, sponge cake 47 grams, sliced oranges 82 grams.
Food. | Grams. | Per cent Nitrogen. | Total Nitrogen. | ||||
---|---|---|---|---|---|---|---|
Coffee | 64 + 137 = | 201.5 | × | 0.042 | = | 0.085 | gram. |
Cream | 30.5 | × | 0.41 | = | 0.125 | ||
Sugar | 12 + 9 + 7 = | 28.0 | × | 0.00 | = | 0.000 | |
Chicken | 50.0 | × | 4.70 | = | 2.350 | ||
Mashed potato | 131.0 | × | 0.30 | = | 0.393 | ||
Biscuit | 35 + 49 = | 84.0 | × | 1.49 | = | 1.251 | |
Butter | 13 + 6 = | 19.0 | × | 0.10 | = | 0.019 | |
Chocolate pudding | 106.0 | × | 0.86 | = | 0.911 | ||
Cheese crackers | 29.0 | × | 2.54 | = | 0.737 | ||
Lettuce sandwich | 56.0 | × | 0.92 | = | 0.515 | ||
Tea | 170.0 | × | 0.048 | = | 0.082 | ||
Sponge cake | 47.0 | × | 0.98 | = | 0.461 | ||
Sliced orange | 82.0 | × | 0.073 | = | 0.060 | ||
Total nitrogen in food | 6.989 | grams. | |||||
Total nitrogen in urine | 5.910 |
Fuel value of the food | 1708 calories.[32] |
Monday, March 21, 1904.
Breakfast, 7.45 A. M.—Coffee 119 grams, cream 30 grams, sugar 9 grams.
Lunch, 1.30 P. M.—One shredded wheat biscuit 31 grams, cream 116 grams, wheat gems 33 grams, butter 7 grams, tea 185 grams, sugar 10 grams, cream cake 53 grams.
Dinner, 6.30 P. M.—Pea soup 114 grams, lamb chop 24 grams, boiled sweet potato 47 grams, wheat gems 76 grams, butter 13 grams, cream cake 52 grams, coffee 61 grams, sugar 10 grams, cheese crackers 16 grams.
Food. | Grams. | Per cent Nitrogen. | Total Nitrogen. | ||||
---|---|---|---|---|---|---|---|
Coffee | 119 + 61 = | 180 | × | 0.042 | = | 0.076 | gram. |
Cream | 30 + 116 = | 146 | × | 0.41 | = | 0.600 | |
Sugar | 9 + 10 + 10 = | 29 | × | 0.00 | = | 0.000 | |
Shredded wheat biscuit | 31 | × | 1.62 | = | 0.502 | ||
Tea | 185 | × | 0.048 | = | 0.089 | ||
Wheat gems | 33 + 76 = | 109 | × | 1.46 | = | 1.591 | |
Butter | 7 + 13 = | 20 | × | 0.10 | = | 0.020 | |
Cream cake | 53 + 52 = | 105 | × | 0.97 | = | 1.018 | |
Pea soup | 114 | × | 1.00 | = | 1.140 | ||
Lamb chop | 24 | × | 4.54 | = | 1.090 | ||
Sweet potato | 47 | × | 0.18 | = | 0.085 | ||
Cheese crackers | 16 | × | 2.54 | = | 0.410 | ||
Total nitrogen in food | 6.621 | grams. | |||||
Total nitrogen in urine | 5.520 |
Fuel value of the food | 1713 calories. |
Tuesday, March 22, 1904.
Breakfast, 7.45 A. M.—Coffee 97 grams, cream 26 grams, sugar 9 grams.
Lunch, 1.30 P. M.—Baked potato 83 grams, fried sausage 36 grams, soda biscuit 39 grams, butter 12 grams, tea 137 grams, sugar 10 grams, cream meringue 59 grams.
Dinner, 6.30 P. M.—Chicken broth 146 grams, bread 52 grams, butter 15 grams, creamed potato 76 grams, custard 76 grams, coffee 50 grams, sugar 11 grams, cheese crackers 10 grams.
Food. | Grams. | Per cent Nitrogen. | Total Nitrogen. | ||||
---|---|---|---|---|---|---|---|
Coffee | 97 + 50 = | 147 | × | 0.042 | = | 0.060 | gram. |
Cream | 26 | × | 0.42 | = | 0.109 | ||
Sugar | 9 + 10 + 11 = | 30 | × | 0.00 | = | 0.000 | |
Baked potato | 83 | × | 0.40 | = | 0.332 | ||
Fried sausage | 36 | × | 3.06 | = | 1.101 | ||
Soda biscuit | 39 | × | 1.66 | = | 0.647 | ||
Butter | 12 + 15 = | 27 | × | 0.10 | = | 0.027 | |
Tea | 137 | × | 0.048 | = | 0.066 | ||
Cream meringue | 59 | × | 0.92 | = | 0.543 | ||
Chicken broth | 146 | × | 0.78 | = | 1.138 | ||
Bread | 52 | × | 1.66 | = | 0.863 | ||
Creamed potato | 76 | × | 0.42 | = | 0.319 | ||
Custard | 76 | × | 0.82 | = | 0.623 | ||
Cheese crackers | 10 | × | 2.54 | = | 0.254 | ||
Total nitrogen in food | 6.082 | grams. | |||||
Total nitrogen in urine | 5.940 |
Fuel value of the food | 1398 calories. |
Wednesday, March 23, 1904.
Breakfast, 7.45 A. M.—Coffee 103 grams, cream 30 grams, sugar 10 grams.
Lunch, 1.30 P. M.—Creamed codfish 64 grams, potato balls 54 grams, biscuit 44 grams, butter 22 grams, tea 120 grams, sugar 10 grams, wheat griddle cakes 133 grams, maple syrup 108 grams.
Dinner, 6.30 P. M.—Creamed potato 85 grams, biscuit 53 grams, butter 15 grams, apple-celery-lettuce salad 50 grams, apple pie 127 grams, coffee 67 grams, sugar 8 grams, cheese crackers 17 grams.
Food. | Grams. | Per cent Nitrogen. | Total Nitrogen. | ||||
---|---|---|---|---|---|---|---|
Coffee | 103 + 67 = | 170 | × | 0.042 | = | 0.071 | gram. |
Sugar | 10 + 10 + 8 = | 28 | × | 0.00 | = | 0.000 | |
Cream | 30 | × | 0.43 | = | 0.129 | ||
Potato balls | 54 | × | 0.68 | = | 0.367 | ||
Creamed codfish | 64 | × | 1.26 | = | 0.806 | ||
Biscuit | 44 + 53 = | 97 | × | 1.66 | = | 1.610 | |
Butter | 22 + 15 = | 37 | × | 0.10 | = | 0.037 | |
Tea | 120 | × | 0.048 | = | 0.058 | ||
Wheat griddle cakes | 133 | × | 1.32 | = | 1.760 | ||
Maple syrup | 108 | × | 0.019 | = | 0.021 | ||
Creamed potato | 85 | × | 0.53 | = | 0.450 | ||
Cheese crackers | 17 | × | 2.54 | = | 0.431 | ||
Apple-celery salad | 50 | × | 0.20 | = | 0.100 | ||
Apple pie | 127 | × | 0.75 | = | 0.953 | ||
Total nitrogen in food | 6.793 | grams. | |||||
Total nitrogen in urine | 5.610 |
Fuel value of the food | 1984 calories. |
Thursday, March 24, 1904.
Breakfast, 7.45 A. M.—Coffee 100 grams, cream 25 grams, sugar 8 grams.
Lunch, 1.30 P. M.—Shredded wheat biscuit 29 grams, cream 118 grams, wheat gems 60 grams, butter 8 grams, tea 100 grams, sugar 7 grams, apple pie 102 grams.
Dinner, 6.30 P. M.—Milk-celery soup 140 grams, bread 15 grams, butter 1 gram, lettuce sandwiches 62 grams, tea 100 grams, sugar 10 grams, lemon pie 109 grams.
Food. | Grams. | Per cent Nitrogen. | Total Nitrogen. | ||||
---|---|---|---|---|---|---|---|
Coffee | 100 | × | 0.042 | = | 0.042 | gram. | |
Cream | 25 + 118 = | 143 | × | 0.43 | = | 0.615 | |
Sugar | 8 + 7 + 10 = | 25 | × | 0.00 | = | 0.000 | |
Shredded wheat biscuit | 29 | × | 1.76 | = | 0.510 | ||
Wheat gems | 60 | × | 1.17 | = | 0.702 | ||
Butter | 8 + 1 = | 9 | × | 0.10 | = | 0.009 | |
Tea | 100 + 100 = | 200 | × | 0.048 | = | 0.096 | |
Apple pie | 102 | × | 0.75 | = | 0.765 | ||
Milk-celery soup | 140 | × | 0.42 | = | 0.588 | ||
Bread | 15 | × | 1.36 | = | 0.204 | ||
Lettuce sandwich | 62 | × | 1.02 | = | 0.632 | ||
Lemon pie | 109 | × | 0.82 | = | 0.894 | ||
Total nitrogen in food | 5.057 | grams. | |||||
Total nitrogen in urine | 4.310 |
Fuel value of the food | 1594 calories. |
Friday, March 25, 1904.
Breakfast, 7.45 A. M.—Coffee 100 grams, cream 25 grams, sugar 9 grams.
Lunch, 1.30 P. M.—Halibut with egg sauce 108 grams, mashed potato 89 grams, biscuit 48 grams, butter 10 grams, chocolate-cream cake 90 grams, tea 100 grams, sugar 9 grams.
Dinner, 6.30 P. M.—Milk-celery soup 121 grams, lettuce sandwiches 61 grams, creamed potato 65 grams, lettuce-apple-celery salad 74 grams, coffee 70 grams, sugar 10 grams.
Food. | Grams. | Per cent Nitrogen. | Total Nitrogen. | ||||
---|---|---|---|---|---|---|---|
Coffee | 100 + 70 = | 170 | × | 0.042 | = | 0.071 | gram. |
Cream | 25 | × | 0.40 | = | 0.100 | ||
Sugar | 9 + 9 + 10 = | 28 | × | 0.00 | = | 0.000 | |
Halibut, etc. | 108 | × | 3.02 | = | 3.262 | ||
Mashed potato | 89 | × | 0.26 | = | 0.231 | ||
Biscuit | 48 | × | 1.52 | = | 0.730 | ||
Butter | 10 | × | 0.10 | = | 0.010 | ||
Tea | 100 | × | 0.048 | = | 0.048 | ||
Chocolate-cream cake | 90 | × | 0.99 | = | 0.891 | ||
Celery-milk soup | 121 | × | 0.52 | = | 0.629 | ||
Lettuce sandwich | 61 | × | 0.98 | = | 0.598 | ||
Lettuce-apple salad | 74 | × | 0.21 | = | 0.155 | ||
Creamed potato | 65 | × | 0.37 | = | 0.241 | ||
Total nitrogen in food | 6.966 | grams. | |||||
Total nitrogen in urine | 5.390 |
Fuel value of the food | 1285 calories. |
NITROGEN BALANCE.—Chittenden.
Nitrogen Taken in. |
Output. | ||||||
---|---|---|---|---|---|---|---|
Nitrogen in Urine. | Weight of Fæces[33] (dry). | ||||||
March | 20 | 6.989 | grams. | 5.91 | grams. | 3.6 | grams. |
21 | 6.621 | 5.52 | 0.0 | ||||
22 | 6.082 | 5.94 | 12.0 | ||||
23 | 6.793 | 5.61 | 18.5 | ||||
24 | 5.057 | 4.31 | 23.0 | ||||
25 | 6.966 | 5.39 | 16.9 | ||||
74.0 | grams contain 6.42% N. |
||||||
38.508 | 32.68 | + | 4.75 | grams nitrogen. | |||
38.508 | grams nitrogen. | 37.43 | grams nitrogen. |
Nitrogen balance for six days | = | +1.078 | grams. |
Nitrogen balance per day | = | +0.179 | gram. |
Average Intake.
Calories per day | 1613. |
Nitrogen per day | 6.40 grams. |
Examination of the results shown in the foregoing balance makes it quite clear that the body was essentially in nitrogenous equilibrium. Indeed, there was a slight plus balance, showing that even with the small intake of proteid food the body was storing up nitrogen at the rate of 0.16 gram per day. The average daily intake of nitrogen for the six days’ period was 6.40 grams, equal to 40.0 grams of proteid or albuminous food. The average daily output of nitrogen through the urine and fæces was 6.24 grams. The average daily output of nitrogen through the urine for the six days’ period was 5.44 grams, corresponding to the metabolism of 34 grams of proteid material. When these figures are contrasted with the usually accepted standards of proteid requirement for the healthy man, they are certainly somewhat impressive, especially when it is remembered that the body at that date had been in essentially this same condition for at least six months, and probably for an entire year. The Voit standard of 118 grams of proteid, with an equivalent of at least 18 grams of nitrogen and calling for the metabolism of 105 grams of proteid, or 16.5 grams of nitrogen per day, makes clear how great a physiological economy had been accomplished. In other words, the consumption of proteid food was reduced to at least one-third the daily amount generally considered as representing the average requirement of the healthy man, and this with maintenance of body-weight at practically a constant point for the preceding ten months, and, so far as the writer can observe, with no loss of vigor, capacity for mental and physical work, or endurance. Indeed, the writer is disposed to maintain that he has done more work and led a more active life in every way during the period of this experiment, and with greater comfort and less fatigue than usual. His health has certainly been of the best during this period.
In this connection it may be well to call attention to the completeness of the utilization of the daily food in this six days’ experiment, as shown by the small amount of refuse discharged per rectum, indicating as it does the high efficiency of the digestive processes and of the processes of absorption.[42] The refuse matter for the entire period of six days amounted when dry to only 74 grams, and when it is remembered how large a proportion of this refuse must of necessity be composed of the cast-off secretions from the body, it will be seen how thorough must have been the utilization of the food by the system. The loss of nitrogen to the body per day through the fæces amounted to only 0.79 gram, and this on a mixed diet containing considerable matter not especially concentrated, and on some days with noticeable amounts of food, such as salads, not particularly digestible.
Finally, emphasis should be laid upon the fact that this economy of proteid food, this establishment of nitrogen equilibrium on a low proteid intake, was accomplished without increase in the daily intake of non-nitrogenous foods. In fact, the amount of fats and carbohydrates was likewise greatly reduced, far below the minimal standard of 3000 calories as representing the potential energy or fuel value of the daily diet. Indeed, during the balance period of six days just described the average fuel value of the food per day was only a little over 1600 calories.
As the experiment continued and the record for the months of April and May was obtained, it became evident from the nitrogen results that the rate of proteid katabolism was being still more reduced. A second balance experiment was therefore tried with a view to seeing if the body was still in nitrogen equilibrium, and also to ascertain whether the fuel value of the food still showed the same low calorific power. For a period of five days, June 23 to 27, the intake of food and the entire output were carefully compared, with the results shown in the accompanying tables.
Thursday, June 23, 1904.
Breakfast.—Coffee 123 grams, cream 50 grams, sugar 11 grams.
Lunch.—Omelette 50 grams, French fried potatoes 70 grams, bacon 10 grams, wheat gems 43 grams, butter 9 grams, strawberries 125 grams, sugar 20 grams, cream cake 59 grams.
Dinner.—Beefsteak 34 grams, peas 60 grams, creamed potato 97 grams, bread 26 grams, butter 17 grams, lettuce-orange salad 153 grams, crackers 43 grams, cream cheese 15 grams, coffee 53 grams, sugar 12 grams.
Food. | Grams. | Per cent Nitrogen. | Total Nitrogen. | ||||
---|---|---|---|---|---|---|---|
Coffee | 123 + 53 = | 176 | × | 0.045 | = | 0.079 | gram. |
Cream | 50 | × | 0.35 | = | 0.175 | ||
Sugar | 11 + 20 + 12 = | 43 | × | 0.00 | = | 0.000 | |
Omelette | 50 | × | 1.32 | = | 0.660 | ||
French fried potatoes | 70 | × | 0.37 | = | 0.259 | ||
Bacon | 10 | × | 3.43 | = | 0.343 | ||
Wheat gems | 43 | × | 1.49 | = | 0.641 | ||
Butter | 9 + 17 = | 26 | × | 0.13 | = | 0.034 | |
Strawberries | 125 | × | 0.11 | = | 0.138 | ||
Cream cake | 59 | × | 0.98 | = | 0.578 | ||
Beefsteak | 34 | × | 4.14 | = | 1.408 | ||
Peas | 60 | × | 0.97 | = | 0.582 | ||
Creamed potato | 97 | × | 0.34 | = | 0.330 | ||
Bread | 26 | × | 1.23 | = | 0.320 | ||
Lettuce-orange salad | 153 | × | 0.15 | = | 0.230 | ||
Crackers | 43 | × | 1.40 | = | 0.602 | ||
Cream cheese | 15 | × | 1.62 | = | 0.243 | ||
Total nitrogen in food | 6.622 | grams. | |||||
Total nitrogen in urine | 5.260 |
Fuel value of the food | 1863 calories. |
Friday, June 24, 1904.
Breakfast.—Coffee 96 grams, sugar 8 grams, milk 32 grams.
Lunch.—Creamed codfish 89 grams, baked potato 95 grams, butter 10 grams, hominy gems 58 grams, strawberries 86 grams, sugar 26 grams, ginger snaps 47 grams.
Dinner.—Cold tongue 14 grams, fried potato 48 grams, peas 60 grams, wheat gems 30 grams, butter 11 grams, lettuce-orange salad with mayonnaise dressing 155 grams, crackers 22 grams, cream cheese 14 grams, ginger snaps 22 grams, coffee 58 grams, sugar 10 grams.
Food. | Grams. | Per cent Nitrogen. | Total Nitrogen. | ||||
---|---|---|---|---|---|---|---|
Coffee | 123 + 53 = | 176 | × | 0.045 | = | 0.079 | gram. |
Sugar | 8 + 26 + 10 = | 44 | × | 0.00 | = | 0.000 | |
Milk | 32 | × | 0.51 | = | 0.163 | ||
Creamed codfish | 89 | × | 1.78 | = | 1.584 | ||
Baked potato | 95 | × | 0.29 | = | 0.276 | ||
Butter | 10 + 11 = | 21 | × | 0.13 | = | 0.027 | |
Hominy gems | 58 | × | 1.20 | = | 0.696 | ||
Strawberries | 86 | × | 0.11 | = | 0.095 | ||
Ginger snaps | 47 + 22 = | 69 | × | 1.15 | = | 0.794 | |
Cold tongue | 14 | × | 4.87 | = | 0.682 | ||
Fried potato | 48 | × | 0.37 | = | 0.178 | ||
Peas | 60 | × | 0.94 | = | 0.564 | ||
Wheat gems | 30 | × | 1.45 | = | 0.435 | ||
Lettuce-orange salad, etc. | 155 | × | 0.15 | = | 0.233 | ||
Crackers | 22 | × | 1.40 | = | 0.308 | ||
Cream cheese | 14 | × | 1.62 | = | 0.227 | ||
Total nitrogen in food | 6.331 | grams. | |||||
Total nitrogen in urine | 5.300 |
Fuel value of the food | 1506 calories. |
Saturday, June 25, 1904.
Breakfast.—Coffee 101 grams, milk 36 grams, sugar 13 grams.
Lunch.—Omelette 50 grams, bacon 9 grams, French fried potato 23 grams, biscuit 29 grams, butter 8 grams, cream cheese 17 grams, iced tea 150 grams, sugar 15 grams, ginger snaps 42 grams.
Dinner.—Wheat popovers 57 grams, butter 10 grams, lettuce-orange salad with mayonnaise dressing 147 grams, cream cheese 21 grams, crackers 22 grams, cottage pudding 82 grams, coffee 48 grams, sugar 11 grams.
Food. | Grams. | Per cent Nitrogen. | Total Nitrogen. | ||||
---|---|---|---|---|---|---|---|
Coffee | 1201 + 48 = | 149 | × | 0.045 | = | 0.067 | gram. |
Milk | 36 | × | 0.46 | = | 0.166 | ||
Sugar | 13 + 15 + 11 = | 39 | × | 0.00 | = | 0.000 | |
Omelette | 50 | × | 1.42 | = | 0.710 | ||
Bacon | 9 | × | 2.66 | = | 0.239 | ||
French fried potato | 23 | × | 0.57 | = | 0.131 | ||
Biscuit | 29 | × | 1.35 | = | 0.392 | ||
Butter | 8 + 10 = | 18 | × | 0.13 | = | 0.023 | |
Iced tea | 150 | × | 0.018 | = | 0.027 | ||
Ginger snaps | 42 | × | 1.15 | = | 0.483 | ||
Cream cheese | 17 + 21 = | 38 | × | 1.62 | = | 0.616 | |
Wheat popovers | 57 | × | 1.64 | = | 0.935 | ||
Lettuce-orange salad | 147 | × | 0.15 | = | 0.221 | ||
Crackers | 22 | × | 1.40 | = | 0.308 | ||
Cottage pudding | 82 | × | 0.76 | = | 0.623 | ||
Total nitrogen in food | 4.941 | grams. | |||||
Total nitrogen in urine | 4.430 |
Fuel value of the food | 1392 calories. |
Sunday, June 26, 1904.
Breakfast.—Coffee 122 grams, cream 31 grams, sugar 8 grams.
Dinner.—Roast lamb 50 grams, baked potato 52 grams, peas 64 grams, biscuit 32 grams, butter 12 grams, lettuce salad 43 grams, cream cheese 21 grams, toasted crackers 23 grams, blanc mange 164 grams.
Supper.—Iced tea 225 grams, sugar 29 grams, lettuce sandwich 51 grams, strawberries 130 grams, sugar 22 grams, cream 40 grams, sponge cake 31 grams.
Food. | Grams. | Per cent Nitrogen. | Total Nitrogen. | ||||
---|---|---|---|---|---|---|---|
Coffee | 122 | × | 0.045 | = | 0.055 | gram. | |
Cream | 31 + 40 = | 71 | × | 0.32 | = | 0.227 | |
Sugar | 8 + 26 + 10 = | 44 | × | 0.00 | = | 0.000 | |
Roast lamb | 50 | × | 4.28 | = | 2.140 | ||
Baked potato | 52 | × | 0.29 | = | 0.151 | ||
Peas | 64 | × | 1.04 | = | 0.666 | ||
Biscuit | 32 | × | 1.35 | = | 0.432 | ||
Butter | 12 | × | 0.13 | = | 0.016 | ||
Lettuce salad | 43 | × | 0.23 | = | 0.099 | ||
Cream cheese | 21 | × | 1.62 | = | 0.340 | ||
Toasted crackers | 23 | × | 1.36 | = | 0.313 | ||
Blanc mange | 164 | × | 0.35 | = | 0.574 | ||
Iced tea | 225 | × | 0.018 | = | 0.041 | ||
Lettuce sandwich | 51 | × | 0.85 | = | 0.434 | ||
Strawberries | 130 | × | 0.11 | = | 0.143 | ||
Sponge cake | 31 | × | 0.94 | = | 0.291 | ||
Total nitrogen in food | 5.922 | grams. | |||||
Total nitrogen in urine | 4.660 |
Fuel value of the food | 1533 calories. |
Monday, June 27, 1904.
Breakfast.—Coffee 112 grams, cream 22 grams, sugar 10 grams.
Lunch.—Roast lamb 9 grams, baked potato 90 grams, wheat gems 47 grams, butter 12 grams, sugar 25 grams, iced tea 250 grams, vanilla éclair 47 grams.
Dinner.—Lamb chop 32 grams, asparagus 49 grams, butter 17 grams, creamed potato 107 grams, bread 35 grams, lettuce-orange salad with mayonnaise dressing 150 grams, cream cheese 12 grams, crackers 21 grams, coffee 63 grams, sugar 9 grams.
Food. | Grams. | Per cent Nitrogen. | Total Nitrogen. | ||||
---|---|---|---|---|---|---|---|
Coffee | 123 + 53 = | 176 | × | 0.045 | = | 0.079 | gram. |
Cream | 22 | × | 0.32 | = | 0.070 | ||
Sugar | 10 + 25 + 9 = | 44 | × | 0.00 | = | 0.000 | |
Iced tea | 250 | × | 0.018 | = | 0.045 | ||
Baked potato | 90 | × | 0.25 | = | 0.225 | ||
Wheat gems | 47 | × | 1.65 | = | 0.776 | ||
Butter | 12 + 17 = | 29 | × | 0.13 | = | 0.038 | |
Roast lamb | 9 | × | 4.28 | = | 0.385 | ||
Vanilla éclair | 47 | × | 0.85 | = | 0.400 | ||
Lamb chops | 32 | × | 4.57 | = | 1.462 | ||
Asparagus | 49 | × | 0.59 | = | 0.289 | ||
Creamed potato | 107 | × | 0.40 | = | 0.428 | ||
Bread | 35 | × | 1.33 | = | 0.466 | ||
Lettuce-orange salad, etc. | 150 | × | 0.23 | = | 0.345 | ||
Cream cheese | 12 | × | 1.62 | = | 0.194 | ||
Crackers | 21 | × | 1.35 | = | 0.284 | ||
Total nitrogen in food | 5.486 | grams. | |||||
Total nitrogen in urine | 4.980 |
Fuel value of the food | 1454 calories. |
NITROGEN BALANCE.—Chittenden.
Nitrogen Taken in. |
Output. | ||||||
---|---|---|---|---|---|---|---|
Nitrogen in Urine. | Weight of Fæces (dry). | ||||||
June | 23 | 6.622 | grams. | 5.26 | grams. | 10.6 | grams. |
24 | 6.331 | 5.30 | 0.7 | ||||
25 | 4.941 | 4.43 | 14.2 | ||||
26 | 5.922 | 4.66 | 11.9 | ||||
27 | 5.486 | 4.98 | 15.2 | ||||
82.6 | grams contain 6.08% N. |
||||||
29.302 | 24.63 | + | 5.022 | grams nitrogen. | |||
29.302 | grams nitrogen. | 29.652 | grams nitrogen. |
Nitrogen balance for five days | = | -0.350 | gram. |
Nitrogen balance per day | = | -0.070 | gram. |
Average Intake.
Calories per day | 1549. |
Nitrogen per day | 5.860 grams. |
Examination of these figures makes quite clear that the body was still in nitrogen equilibrium, or essentially so, the minus balance being so small as to have little significance. The body-weight was still stationary, and yet during this balance period the average daily intake of nitrogen was only 5.86 grams, corresponding to 36.62 grams of proteid or albuminous food. Further, the average daily fuel value of the food was only 1549 calories, a trifle less than in the preceding period. The average daily output of nitrogen through the urine for this period was 4.92 grams, corresponding to the metabolism of 30.7 grams of proteid food. Hence, the results of this period confirm those of the preceding period and make it quite clear that this subject, with a body-weight of 57.5 kilos, can be maintained in body equilibrium, and in nitrogen equilibrium, on a daily diet containing only 5.8 grams of nitrogen and with a fuel value of about 1600 calories. Under these conditions, as in the last balance period, the daily amount of nitrogen metabolized was very small, averaging only 4.92 grams. Comparison of this figure with the accepted standard of 16 grams of nitrogen makes quite clear the extent of the physiological economy which is attainable by the body, and emphasizes also the extent of the unnecessary and worse than useless labor put upon the body by the prevalent dietetic habits of the majority of mankind.
It is of course understood that the low fuel value which sufficed to keep the writer in body equilibrium would not meet the requirements of a more active life, with greater physical labor. The writer has led a very busy life during the year of this experiment, but it has been mental activity rather than physical, although doubtless he has exercised as much as the ordinary professional worker not accustomed to athletic sports. The results of the experiment, however, make it quite clear that a man of the above body-weight, even though he lead a very active life—not involving great physical labor—can maintain his body in equilibrium indefinitely with an intake of 36 to 40 grams of proteid or albuminous food, and with a total fuel value of about 1600 calories. Further, it is to be[50] understood that there is no special form of diet involved in the accomplishment of such a result. Scrutiny of the daily diet, tabulated in the two balance periods, will show the character of the food made use of. Personal likes and dislikes must naturally enter into the choice of any diet, and freedom of choice, freedom to follow the dictates of one’s appetite, with such regulation as comes from the use of reason and intelligence, are all that is necessary to secure the desired end. Physiological economy in nutrition is easily attainable and does not involve the adoption of vegetarianism. It does mean, however, temperance and simplicity in diet, coupled with intelligent regulation, which, however, soon becomes a habit and eventually leads to a moderation in diet which fully satisfies all the cravings of appetite as completely as it suffices to maintain the body in equilibrium and in a general condition of health and vigor.
Taking the data recorded above, we may now calculate the nitrogen requirement of the body per kilo of body-weight. With the body-weight placed at 57 kilos and with an average daily elimination of nitrogen for nearly nine months of 5.699 grams, or practically 5.7 grams, it is evident that the nitrogen metabolized per kilo of body-weight in the present instance was exactly 0.1 gram. If we take the lower figure of 5.40 grams of nitrogen, the average daily excretion from April 13 to June 27, we find the nitrogen requirement to be 0.0947 gram per kilo of body-weight. Translating these figures into terms of proteid or albuminous matter, they mean the utilization or metabolism of 0.625 gram of proteid matter daily per kilo of body-weight, under the conditions of life, activity, and general food consumption prevailing throughout this period of nearly nine months with this particular individual.
Whether we are justified in saying that this figure represents the minimal proteid requirement of this particular individual is perhaps questionable, since the proteid or nitrogen requirement will of necessity vary somewhat with the amount of non-nitrogenous food consumed. Doubtless, the nitrogen metabolism could be reduced still lower by increasing[51] the intake of non-nitrogenous food, but under the above conditions of life, following a plan of living both congenial and satisfactory, one that fully sufficed to keep the body in equilibrium and with the practice of a general physiological economy, we may say that the metabolism of 0.1 gram of nitrogen per kilo of body-weight was quite sufficient to meet all the requirements of the body. Health, strength, mental and physical vigor have been maintained unimpaired, and there is a growing conviction that in many ways there is a distinct improvement in both the physical and mental condition. Greater freedom from fatigue, greater aptitude for work, greater freedom from minor ailments, have gradually become associated in the writer’s mind with this lowered proteid metabolism and general condition of physiological economy. The writer, however, is fully alive to the necessity of caution in the acceptance of one’s feelings as a measure of physical or mental condition, but he has been keenly watchful for any and every sign or symptom during the course of these experiments, and is now strongly of the opinion that there is much good to be gained in the adoption of dietetic habits that accord more closely with the true physiological needs of the body. If a man of 57 kilos body-weight can maintain a condition of equilibrium, with continuance of health, strength, and vigor (to say nothing of possible improvement), with a daily consumption of say 40 grams of proteid food and sufficient non-nitrogenous food to yield 2000 calories, why should he load up his system each day with three times this amount of proteid food, with enough more fat and carbohydrate to yield 3000 plus calories?
Finally, the writer in summing up his own experience is inclined to say that while he entered upon this experiment simply with a view to studying the question from a purely scientific and physiological standpoint, he has become so deeply impressed with the great gain to the body by this practice of physiological economy, and his system has become so accustomed to the new level of nutrition that there is no desire to return to the more liberal dietetic habits of former years.
Obviously, it is not wise nor safe to draw too broad deductions from a single individual, nor from a single experiment even though it extends over a long period of time; consequently, we may turn our attention to other individuals with presumably different personality and different habits of life. The writer’s colleague, Dr. Lafayette B. Mendel, Professor of Physiological Chemistry in the Sheffield Scientific School, kindly volunteered to become a subject of experiment. With a body-weight of 76 kilos, 32 years of age, and of strong physique, he commenced to modify his diet about the middle of October, 1903, diminishing gradually the amount of proteid food with the results shown in the following tables, where are given, as in the preceding experiment, the amounts of nitrogen in the urine, as a measure of the quantity of proteid metabolized, uric acid, and other factors of interest in this connection.
The collection of data commenced on October 26, 1903. During some weeks the urine of each day was not analyzed by itself, but an aliquot part was taken from the 24 hours’ quantity, and at the end of a week the determinations were made on the mixture, thereby giving the average daily composition for the period. With Dr. Mendel, as in the writer’s case, there was no prescribing of food, but perfect freedom of choice. The appetite was satisfied each day, but with a gradual diminution of proteid food, especially of meat. Dr. Mendel appeared to accomplish the desired end best by keeping up a liberal allowance of non-nitrogenous food, and the total potential energy of the daily diet was not so greatly diminished as in the writer’s case. In other words, he appeared to need more food, but succeeded without great effort in reducing the proteid intake to nearly as low a level as in the preceding experiment. For the period of three months from January 4 to April 3, 1904, the average daily excretion of nitrogen amounted to 6.46 grams, which means the metabolism of 40.37 grams of proteid or albuminous food per day for this quarter of the year.
From November 10, 1903, to June 23, 1904, a period of about seven months and a half, the average daily excretion of nitrogen through the urine was 6.53 grams. In other words, throughout this long period the average daily amount of proteid matter metabolized was 40.8 grams, only a little more than one-third the amount called for by the Voit standard. Until February, the body-weight gradually fell, but from the early part of February until the end of the experiment the body-weight remained practically stationary at 70 kilos. Dr. Mendel, however, from the necessities of his daily work in the laboratory was compelled to a much greater degree of physical activity than the subject of the preceding experiment, and consequently required a larger amount of non-nitrogenous food than the latter. Further, owing to his greater physical activity and the necessary variations in this daily activity, it was not so easy at first to attain equilibrium.
On February 9, a balance experiment of six days was commenced, with a careful comparison of the nitrogen intake and output. In the accompanying tables are shown all of the data. By scrutiny of these it will be seen that Dr. Mendel had adopted essentially a vegetarian diet. During this period of[60] six days, however, he was not in nitrogen equilibrium, neither was he strictly in body equilibrium, since there was a distinct tendency for the body to fall off in weight. In this connection it may be mentioned that there is always a tendency during a balance experiment of this character for the subject to eat less than he is ordinarily accustomed to, owing to the tediousness of weighing every particle of food consumed. Further, for the same reason, and to avoid excess of chemical work in the analysis of samples of food, he is inclined to limit his diet to a few articles and thereby unconsciously restricts his intake of food, sometimes disastrously so.
Tuesday, February 9, 1904.
Breakfast.—Bread 33 grams, sugar 20 grams, coffee and milk 210 grams.
Lunch.—Consommé 150 grams, sweet potato 170 grams, bread 135 grams, tomato 106 grams, coffee and milk 210 grams, sugar 20 grams.
Dinner.—Bread 75 grams, mashed potato 200 grams, string beans 91 grams, apple pie 282 grams, coffee and milk 210 grams, sugar 20 grams, water 100 grams.
Food. | Grams. | Per cent Nitrogen. | Total Nitrogen. | ||||
---|---|---|---|---|---|---|---|
Bread | 33 + 135 + 75 = | 243 | × | 1.36 | = | 3.30 | grams. |
Sugar | 20 + 20 + 20 = | 60 | × | 0.00 | = | 0.00 | |
Coffee (breakfast) | 210 | × | 0.10 | = | 0.21 | ||
Consommé | 150 | × | 0.38 | = | 0.57 | ||
Sweet potato | 170 | × | 0.28 | = | 0.48 | ||
Tomato | 106 | × | 0.19 | = | 0.20 | ||
Coffee (lunch) | 210 | × | 0.15 | = | 0.32 | ||
Potato | 200 | × | 0.36 | = | 0.72 | ||
String beans | 91 | × | 0.26 | = | 0.24 | ||
Apple pie | 282 | × | 0.49 | = | 1.38 | ||
Coffee (dinner) | 210 | × | 0.099 | = | 0.21 | ||
Total nitrogen in food | 7.63 | grams. | |||||
Total nitrogen in urine | 7.52 |
Fuel value of the food | 2297 calories. |
Wednesday, February 10, 1904.
Breakfast.—Bread 37 grams, sugar 20 grams, coffee and milk 210 grams.
Lunch.—Bread 110 grams, sugar 7 grams, milk 250 grams, apple fritters 90 grams.
Dinner.—Bread 37 grams, sugar 21 grams, baked beans 100 grams, cranberry sauce 125 grams, coffee and milk 210 grams, molasses candy 54 grams.
Food. | Grams. | Per cent Nitrogen. | Total Nitrogen. | ||||
---|---|---|---|---|---|---|---|
Bread | 37 + 110 + 37 = | 184 | × | 1.65 | = | 3.04 | grams. |
Sugar | 20 + 7 + 21 = | 48 | × | 0.00 | = | 0.00 | |
Coffee (breakfast) | 210 | × | 0.12 | = | 0.25 | ||
Milk | 250 | × | 0.55 | = | 1.37 | ||
Apple fritters | 90 | × | 0.45 | = | 0.40 | ||
Baked beans | 100 | × | 1.40 | = | 1.40 | ||
Cranberry sauce | 125 | × | 0.04 | = | 0.05 | ||
Coffee (dinner) | 210 | × | 0.11 | = | 0.23 | ||
Candy | 54 | × | 0.06 | = | 0.03 | ||
Total nitrogen in food | 6.77 | grams. | |||||
Total nitrogen in urine | 6.75 |
Fuel value of the food | 1673 calories. |
Thursday, February 11, 1904.
Breakfast.—Bread 40 grams, sugar 20 grams, coffee and milk 210 grams.
Lunch.—Bread 95 grams, sweet potato 130 grams, sugar 7 grams, milk 250 grams, peach preserve 93 grams.
Dinner.—Bread 90 grams, mashed potato 100 grams, tomato purée 135 grams, baked beans 75 grams, lemon pie 110 grams, coffee and milk 210 grams, sugar 21 grams.
Fuel value of the food | 1828 calories. |
Friday, February 12, 1904.
Breakfast.—Bread 58 grams, sugar 21 grams, coffee and milk 210 grams.
Lunch.—Bread 120 grams, sugar 21 grams, custard 76 grams, milk 250 grams, coffee and milk 125 grams.
Dinner.—Bread 67.5 grams, sugar 21 grams, mashed potato 150 grams, lima beans 80 grams, coffee and milk 210 grams, apple dumpling 131 grams, molasses candy 27 grams.
Food. | Grams. | Per cent Nitrogen. | Total Nitrogen. | ||||
---|---|---|---|---|---|---|---|
Bread | 58 + 120 + 67.5 = | 245.5 | × | 1.71 | = | 4.20 | grams. |
Sugar | 21 + 21 + 21 = | 63.0 | × | 0.00 | = | 0.00 | |
Coffee (breakfast) | 210.0 | × | 0.11 | = | 0.23 | ||
Custard | 76.0 | × | 0.83 | = | 0.63 | ||
Milk | 250.0 | × | 0.48 | = | 1.20 | ||
Coffee (lunch) | 125.0 | × | 0.078 | = | 0.10 | ||
Potato | 150.0 | × | 0.37 | = | 0.56 | ||
Lima beans | 80.0 | × | 0.90 | = | 0.72 | ||
Coffee (dinner) | 210.0 | × | 0.12 | = | 0.25 | ||
Apple dumpling | 131.0 | × | 0.72 | = | 0.94 | ||
Candy | 27.0 | × | 0.06 | = | 0.00 | ||
Total nitrogen in food | 8.83 | grams. | |||||
Total nitrogen in urine | 8.24 |
Fuel value of the food | 1929 calories. |
Saturday, February 13, 1904.
Breakfast.—Bread 47.5 grams, sugar 28 grams, coffee and milk 210 grams.
Lunch.—Bread 57 grams, sugar 40 grams, sweet potato 135 grams, quince preserve 73 grams, apple turnovers 118 grams, coffee and milk 310 grams.
Dinner.—Bread 59 grams, mashed potato 175 grams, peas 80 grams, apple pie 141.5 grams, sugar 21 grams, coffee and milk 210 grams.
Food. | Grams. | Per cent Nitrogen. | Total Nitrogen. | ||||
---|---|---|---|---|---|---|---|
Bread | 47.5 + 57 + 59 = | 164.0 | × | 1.64 | = | 2.69 | grams. |
Sugar | 28 + 40 + 21 = | 89.0 | × | 0.00 | = | 0.00 | |
Coffee (breakfast) | 210.0 | × | 0.11 | = | 0.23 | ||
Sweet potato | 135.0 | × | 0.37 | = | 0.50 | ||
Quince preserve | 73.0 | × | 0.047 | = | 0.03 | ||
Apple turnovers | 118.0 | × | 0.96 | = | 1.13 | ||
Coffee (lunch) | 310.0 | × | 0.15 | = | 0.47 | ||
Potato | 175.0 | × | 0.37 | = | 0.65 | ||
Peas | 80.0 | × | 0.96 | = | 0.77 | ||
Apple pie | 141.5 | × | 0.43 | = | 0.61 | ||
Coffee (dinner) | 210.0 | × | 0.11 | = | 0.23 | ||
Total nitrogen in food | 7.31 | grams. | |||||
Total nitrogen in urine | 7.83 |
Fuel value of the food | 2057 calories. |
Sunday, February 14, 1904.
Breakfast.—Bread 50 grams, sugar 21 grams, banana 92.5 grams, coffee and milk 210 grams.
Lunch.—Bread 108.5 grams, sugar 28 grams, baked potato 165 grams, apple sauce 114 grams, coffee and milk 210 grams.
Dinner.—Bread 63 grams, sugar 28 grams, succotash 75 grams, mashed potato 200 grams, chocolate layer cake 80 grams, ice cream 73 grams, coffee and milk 210 grams.
Food. | Grams. | Per cent Nitrogen. | Total Nitrogen. | ||||
---|---|---|---|---|---|---|---|
Bread | 50 + 108.5 + 63 = | 221.5 | × | 1.75 | = | 3.87 | grams. |
Sugar | 21 + 28 + 28 = | 77.0 | × | 0.00 | = | 0.00 | |
Banana | 92.5 | × | 0.002 | = | 0.19 | ||
Coffee (breakfast) | 210.0 | × | 0.11 | = | 0.23 | ||
Baked potato | 165.0 | × | 0.41 | = | 0.68 | ||
Apple sauce | 114.0 | × | 0.029 | = | 0.03 | ||
Coffee (lunch) | 210.0 | × | 0.10 | = | 0.21 | ||
Succotash | 75.0 | × | 0.57 | = | 0.43 | ||
Mashed potato | 200.0 | × | 0.37 | = | 0.74 | ||
Chocolate cake | 80.0 | × | 0.75 | = | 0.60 | ||
Ice cream | 73.0 | × | 0.58 | = | 0.42 | ||
Coffee (dinner) | 210.0 | × | 0.11 | = | 0.23 | ||
Total nitrogen in food | 7.63 | grams. | |||||
Total nitrogen in urine | 7.99 |
Fuel value of the food | 2065 calories. |
NITROGEN BALANCE.—Mendel.
Nitrogen Taken in. |
Output. | |||||||||
---|---|---|---|---|---|---|---|---|---|---|
Nitrogen in Urine. | Weight of Fæces (dry). | |||||||||
Feb. | 9 | 7.63 | grams. | 7.52 | grams. | |||||
10 | 6.77 | 6.75 | ||||||||
11 | 8.62 | 6.71 | ||||||||
12 | 8.83 | 8.24 | 53 ⎫ | contain 5.84% N | = | 6.248 | grm. N. | |||
13 | 7.31 | 7.83 | 54 ⎭ | |||||||
14 | 7.63 | 7.99 | 39.2 | contain 6.72% N | = | 2.634 | ||||
146.2 | 8.882 | grm. N. | ||||||||
46.79 | 45.04 | + | 8.882 | grams nitrogen. | ||||||
46.79 | grams nitrogen. | 53.92 | grams nitrogen. |
Nitrogen balance for six days | = | -7.13 | grams. |
Nitrogen balance per day | = | -1.19 | grams. |
Average Intake.
Calories per day | 1975. |
Nitrogen per day | 7.83 grams. |
In this balance period of six days the average daily intake of nitrogen was 7.83 grams, coupled with an average fuel value of the food per day of 1975 calories. This latter value was obviously too small for a man of Dr. Mendel’s body-weight, and doing the amount of physical work he was called upon to perform. Being on one’s feet in a laboratory six to eight hours a day, in addition to the ordinary activity of a vigorous man leading a strenuous life, necessitates the utilization and oxidation of considerable food material. The average daily output of nitrogen through the urine amounted to 7.50 grams, considerably above the average daily excretion for the seven months’ period. Still, under these conditions there was a minus balance of 7.13 grams of nitrogen for the six days’ period, indicating that the body was drawing upon its stock of proteid material to the extent of 1.19 grams of nitrogen per day. This does not necessarily mean that the body had need of that additional amount of proteid matter each day, but rather that the amount of total energy required was beyond the potential energy supplied by the food. There not being sufficient non-nitrogenous food at hand, the body was compelled to draw upon its own resources, and in so doing utilized some of its tissue proteid. This is made quite clear by the results of the second balance period shortly to be described.
It is evident, however, that while the body was not in nitrogen equilibrium for this particular period of six days, there must have been a general condition of both body and nitrogen equilibrium, otherwise the body-weight would not have remained practically stationary for so long a period as from February 7 to June 20.
Commencing May 18, a second nitrogen balance was attempted, in which, as in the preceding case, there was a careful comparison of income and output for seven days. There was as before a free choice of food, but it was essentially vegetable in character. A greater variety of foods was taken, however, and an effort was made to have the non-nitrogenous food somewhat more liberal in amount, though in as close harmony as possible with the desires of the appetite.
Wednesday, May 18, 1904.
Breakfast.—Banana 92 grams, bread rolls 28 grams, cream 50 grams, coffee 150 grams, sugar 21 grams.
Lunch.—Bread 66 grams, soup 150 grams, farina 154 grams, sweet potato 123 grams, beans 70 grams, syrup 50 grams, coffee 150 grams, cream 50 grams, sugar 14 grams.
Dinner.—Bread 42 grams, consommé 100 grams, spinach 100 grams, mashed potato 250 grams, apple pie 97 grams, coffee 150 grams, cream 50 grams, sugar 21 grams.
Food. | Grams. | Per cent Nitrogen. | Total Nitrogen. | ||||
---|---|---|---|---|---|---|---|
Banana | 92 | × | 0.23 | = | 0.212 | grams. | |
Bread rolls | 28 | × | 1.66 | = | 0.465 | ||
Cream | 50 | × | 0.46 | = | 0.230 | ||
Coffee | 150 | × | 0.066 | = | 0.099 | ||
Sugar | 21 | × | 0.00 | = | 0.000 | ||
Bread | 66 | × | 1.60 | = | 1.056 | ||
Soup | 150 | × | 0.41 | = | 0.615 | ||
Farina | 154 | × | 1.09 | = | 1.678 | ||
Sweet Potato | 123 | × | 0.32 | = | 0.394 | ||
Beans | 70 | × | 0.34 | = | 0.238 | ||
Syrup | 50 | × | 0.024 | = | 0.012 | ||
Coffee | 150 | × | 0.057 | = | 0.086 | ||
Cream | 50 | × | 0.46 | = | 0.230 | ||
Sugar | 14 | × | 0.00 | = | 0.000 | ||
Bread | 42 | × | 1.80 | = | 0.756 | ||
Consommé | 100 | × | 0.38 | = | 0.380 | ||
Spinach | 100 | × | 0.53 | = | 0.530 | ||
Mashed potato | 250 | × | 0.38 | = | 0.950 | ||
Apple pie | 97 | × | 0.43 | = | 0.417 | ||
Coffee | 150 | × | 0.06 | = | 0.090 | ||
Cream | 50 | × | 0.46 | = | 0.230 | ||
Sugar | 21 | × | 0.00 | = | 0.000 | ||
Total nitrogen in food | 8.668 | grams. | |||||
Total nitrogen in urine | 6.060 |
Fuel value of the food | 2359 calories. |
Thursday, May 19, 1904.
Breakfast.—Banana 102 grams, bread rolls 50 grams, coffee 150 grams, cream 50 grams, sugar 21 grams.
Lunch.—Bread 57 grams, egg omelette 20 grams, hominy 137 grams, syrup 68 grams, potatoes 128 grams, coffee 100 grams, sugar 21 grams, cream 50 grams.
Dinner.—Tomato purée 200 grams, bread 24 grams, fried sweet potato 100 grams, spinach 70 grams, Indian meal 100 grams, syrup 25 grams, coffee 100 grams, sugar 21 grams, cream 40 grams.
Food. | Grams. | Per cent Nitrogen. | Total Nitrogen. | ||||
---|---|---|---|---|---|---|---|
Banana | 102 | × | 0.23 | = | 0.235 | grams. | |
Bread rolls | 50 | × | 1.54 | = | 0.770 | ||
Coffee | 150 | × | 0.06 | = | 0.090 | ||
Cream | 50 | × | 0.47 | = | 0.235 | ||
Sugar | 21 | × | 0.00 | = | 0.000 | ||
Bread | 57 | × | 1.60 | = | 0.912 | ||
Egg Omelette | 20 | × | 1.58 | = | 0.316 | ||
Hominy | 137 | × | 0.20 | = | 0.274 | ||
Syrup | 68 | × | 0.024 | = | 0.016 | ||
Potatoes | 128 | × | 0.49 | = | 0.627 | ||
Coffee | 100 | × | 0.06 | = | 0.060 | ||
Cream | 50 | × | 0.47 | = | 0.235 | ||
Sugar | 21 | × | 0.00 | = | 0.000 | ||
Tomato purée | 200 | × | 0.53 | = | 1.060 | ||
Bread | 24 | × | 1.74 | = | 0.418 | ||
Sweet potato | 100 | × | 0.38 | = | 0.380 | ||
Spinach | 70 | × | 0.56 | = | 0.392 | ||
Indian meal | 100 | × | 0.20 | = | 0.200 | ||
Syrup | 25 | × | 0.024 | = | 0.006 | ||
Coffee | 100 | × | 0.06 | = | 0.060 | ||
Sugar | 21 | × | 0.00 | = | 0.000 | ||
Cream | 40 | × | 0.47 | = | 0.188 | ||
Total nitrogen in food | 6.474 | grams. | |||||
Total nitrogen in urine | 7.170 |
Fuel value of the food | 2072 calories. |
Friday, May 20, 1904.
Breakfast.—Sliced orange 140 grams, coffee 100 grams, cream 30 grams, sugar 21 grams.
Lunch.—Bread 28 grams, mashed potato 250 grams, lima beans 40 grams, coffee 100 grams, sugar 21 grams, cream 30 grams, fried hominy 115 grams, syrup 48 grams.
Dinner.—Bread 19 grams, consommé 150 grams, string beans 140 grams, mashed potato 250 grams, rice croquette 93 grams, cranberry jam 95 grams, coffee 100 grams, sugar 21 grams, cream 30 grams, syrup 25 grams.
Food. | Grams. | Per cent Nitrogen. | Total Nitrogen. | ||||
---|---|---|---|---|---|---|---|
Sliced orange | 140 | × | 0.20 | = | 0.280 | ||
Coffee | 100 | × | 0.06 | = | 0.060 | ||
Cream | 30 | × | 0.44 | = | 0.132 | ||
Sugar | 21 | × | 0.00 | = | 0.000 | ||
Bread | 28 | × | 1.71 | = | 0.479 | ||
Mashed potato | 250 | × | 0.30 | = | 0.750 | ||
Lima beans | 40 | × | 0.76 | = | 0.304 | ||
Coffee | 100 | × | 0.06 | = | 0.060 | ||
Sugar | 21 | × | 0.00 | = | 0.000 | ||
Cream | 30 | × | 0.44 | = | 0.132 | ||
Fried hominy | 115 | × | 0.57 | = | 0.656 | ||
Syrup | 48 | × | 0.024 | = | 0.012 | ||
Bread | 19 | × | 1.97 | = | 0.374 | ||
Consommé | 150 | × | 0.59 | = | 0.885 | ||
String beans | 140 | × | 0.36 | = | 0.504 | ||
Mashed potato | 250 | × | 0.34 | = | 0.850 | ||
Rice croquettes | 93 | × | 1.06 | = | 0.986 | ||
Cranberry jam | 95 | × | 0.03 | = | 0.029 | ||
Coffee | 100 | × | 0.06 | = | 0.060 | ||
Sugar | 21 | × | 0.00 | = | 0.000 | ||
Cream | 30 | × | 0.44 | = | 0.132 | ||
Syrup | 25 | × | 0.024 | = | 0.006 | ||
Total nitrogen in food | 6.691 | grams. | |||||
Total nitrogen in urine | 6.330 |
Fuel value of the food | 1915 calories. |
Saturday, May 21, 1904.
Breakfast.—Banana 153 grams, coffee 150 grams, sugar 21 grams, cream 30 grams.
Lunch.—Bread 25 grams, potato croquette 229 grams, Indian meal 109 grams, tomato 123 grams, syrup 48 grams, coffee 100 grams, sugar 14 grams, cream 20 grams.
Dinner.—Bread 31 grams, bean soup 100 grams, fried potato 200 grams, bacon 5 grams, lettuce-orange salad 47 grams, prunes 137 grams, coffee 100 grams, sugar 21 grams, cream 25 grams, banana 255 grams.
Food. | Grams. | Per cent Nitrogen. | Total Nitrogen. | ||||
---|---|---|---|---|---|---|---|
Banana | 153 | × | 0.23 | = | 0.352 | grams. | |
Coffee | 150 | × | 0.06 | = | 0.090 | ||
Sugar | 21 | × | 0.00 | = | 0.000 | ||
Cream | 30 | × | 0.43 | = | 0.129 | ||
Bread | 25 | × | 1.82 | = | 0.455 | ||
Potato croquette | 229 | × | 0.71 | = | 1.626 | ||
Indian meal | 109 | × | 1.09 | = | 1.188 | ||
Tomato | 123 | × | 0.17 | = | 0.209 | ||
Syrup | 48 | × | 0.024 | = | 0.012 | ||
Coffee | 100 | × | 0.06 | = | 0.060 | ||
Sugar | 14 | × | 0.00 | = | 0.000 | ||
Cream | 20 | × | 0.43 | = | 0.086 | ||
Bread | 31 | × | 1.62 | = | 0.502 | ||
Bean soup | 100 | × | 1.21 | = | 1.210 | ||
Fried potato | 200 | × | 0.60 | = | 1.200 | ||
Bacon | 5 | × | 3.05 | = | 0.153 | ||
Lettuce-orange salad | 47 | × | 0.21 | = | 0.099 | ||
Prunes | 137 | × | 0.16 | = | 0.219 | ||
Coffee | 100 | × | 0.06 | = | 0.060 | ||
Sugar | 21 | × | 0.00 | = | 0.000 | ||
Cream | 25 | × | 0.43 | = | 0.108 | ||
Banana | 255 | × | 0.23 | = | 0.587 | ||
Total nitrogen in food | 8.345 | grams. | |||||
Total nitrogen in urine | 6.780 |
Fuel value of the food | 2485 calories. |
Sunday, May 22, 1904.
Breakfast.—Banana 220 grams, orange 60 grams, coffee 100 grams, sugar 21 grams, cream 25 grams.
Lunch.—Bread 35 grams, potato 300 grams, fried rice 160 grams, syrup 63 grams, ice cream 84 grams, coffee 100 grams, sugar 14 grams.
Dinner.—Cream of celery soup 100 grams, bread 21 grams, mashed potato 250 grams, spinach 40 grams, French fried potato 100 grams, strawberry short-cake 120 grams.
Food. | Grams. | Per cent Nitrogen. | Total Nitrogen. | ||||
---|---|---|---|---|---|---|---|
Banana | 220 | × | 0.23 | = | 0.506 | grams. | |
Orange | 60 | × | 0.20 | = | 0.120 | ||
Coffee | 100 | × | 0.06 | = | 0.060 | ||
Sugar | 21 | × | 0.00 | = | 0.000 | ||
Cream | 25 | × | 0.45 | = | 0.113 | ||
Bread | 35 | × | 1.57 | = | 0.550 | ||
Potato | 300 | × | 0.30 | = | 0.900 | ||
Fried rice | 160 | × | 0.75 | = | 1.200 | ||
Syrup | 63 | × | 0.024 | = | 0.015 | ||
Ice cream | 84 | × | 0.53 | = | 0.445 | ||
Coffee | 100 | × | 0.06 | = | 0.060 | ||
Sugar | 14 | × | 0.00 | = | 0.000 | ||
Cream of celery soup | 100 | × | 0.33 | = | 0.330 | ||
Bread | 21 | × | 1.91 | = | 0.401 | ||
Mashed potato | 250 | × | 0.37 | = | 0.925 | ||
Spinach | 40 | × | 0.55 | = | 0.220 | ||
French fried potato | 100 | × | 0.57 | = | 0.570 | ||
Strawberry short-cake | 120 | × | 0.50 | = | 0.600 | ||
Total nitrogen in food | 7.015 | grams. | |||||
Total nitrogen in urine | 5.700 |
Fuel value of the food | 2321 calories. |
Monday, May 23, 1904.
Breakfast.—Banana 229 grams, coffee 125 grams, sugar 21 grams, cream 25 grams.
Lunch.—Bread 58 grams, apple sauce 125 grams, scrambled egg 15 grams, consommé 75 grams, fried potato 170 grams, rice croquette 197 grams, syrup 68 grams, coffee 100 grams, sugar 21 grams, cream 30 grams.
Dinner.—Bread 72.5 grams, vegetable soup 100 grams, potato croquette 198 grams, bacon 7 grams, string beans 120 grams, water ice 77 grams, coffee 100 grams, cream 30 grams, sugar 14 grams, banana 270 grams.
Food. | Grams. | Per cent Nitrogen. | Total Nitrogen. | ||||
---|---|---|---|---|---|---|---|
Banana | 229 | × | 0.23 | = | 0.527 | grams. | |
Coffee | 125 | × | 0.06 | = | 0.075 | ||
Sugar | 21 | × | 0.00 | = | 0.000 | ||
Cream | 25 | × | 0.45 | = | 0.113 | ||
Bread | 58 | × | 1.63 | = | 0.945 | ||
Apple sauce | 125 | × | 0.02 | = | 0.025 | ||
Scrambled egg | 15 | × | 2.07 | = | 0.311 | ||
Consommé | 75 | × | 0.65 | = | 0.488 | ||
Fried potato | 170 | × | 0.60 | = | 1.020 | ||
Rice croquette | 197 | × | 0.61 | = | 1.202 | ||
Syrup | 68 | × | 0.024 | = | 0.016 | ||
Coffee | 100 | × | 0.06 | = | 0.060 | ||
Sugar | 21 | × | 0.00 | = | 0.000 | ||
Cream | 30 | × | 0.45 | = | 0.135 | ||
Bread | 72.5 | × | 1.75 | = | 1.269 | ||
Soup | 100 | × | 0.70 | = | 0.700 | ||
Potato croquette | 198 | × | 0.77 | = | 1.525 | ||
Bacon | 7 | × | 3.28 | = | 0.230 | ||
String beans | 120 | × | 0.22 | = | 0.264 | ||
Water ice | 77 | × | 0.006 | = | 0.005 | ||
Coffee | 100 | × | 0.06 | = | 0.060 | ||
Cream | 30 | × | 0.45 | = | 0.135 | ||
Sugar | 14 | × | 0.00 | = | 0.000 | ||
Banana | 270 | × | 0.23 | = | 0.621 | ||
Total nitrogen in food | 9.726 | grams. | |||||
Total nitrogen in urine | 5.750 |
Fuel value of the food | 2756 calories. |
Tuesday, May 24, 1904.
Breakfast.—Orange 100 grams, rolls 37 grams, rice 50 grams, syrup 25 grams, coffee 125 grams, sugar 21 grams, cream 50 grams.
Lunch.—Bread 77 grams, cream of celery soup 125 grams, mashed potato 270 grams, tomato sauce 50 grams, farina croquette 191 grams, syrup 78 grams, coffee 75 grams, cream 20 grams, sugar 7 grams.
Dinner.—Bread 49 grams, tomato soup 200 grams, French fried potato 200 grams, spinach 50 grams, farina croquette 276 grams, syrup 100 grams, coffee 100 grams, sugar 14 grams, cream 50 grams.
Food. | Grams. | Per cent Nitrogen. | Total Nitrogen. | ||||
---|---|---|---|---|---|---|---|
Orange | 100 | × | 0.20 | = | 0.200 | grams. | |
Bread rolls | 37 | × | 1.64 | = | 0.607 | ||
Rice | 50 | × | 0.36 | = | 0.180 | ||
Syrup | 25 | × | 0.024 | = | 0.006 | ||
Coffee | 125 | × | 0.06 | = | 0.075 | ||
Sugar | 21 | × | 0.00 | = | 0.000 | ||
Cream | 50 | × | 0.45 | = | 0.225 | ||
Bread | 77 | × | 1.66 | = | 1.278 | ||
Celery soup | 125 | × | 0.48 | = | 0.600 | ||
Mashed potato | 270 | × | 0.26 | = | 0.702 | ||
Tomato sauce | 50 | × | 0.23 | = | 0.115 | ||
Farina croquette | 191 | × | 0.74 | = | 1.413 | ||
Syrup | 78 | × | 0.024 | = | 0.019 | ||
Coffee | 75 | × | 0.06 | = | 0.045 | ||
Cream | 20 | × | 0.45 | = | 0.090 | ||
Sugar | 7 | × | 0.00 | = | 0.000 | ||
Bread | 49 | × | 1.82 | = | 0.892 | ||
Tomato soup | 200 | × | 0.19 | = | 0.380 | ||
French fried potato | 200 | × | 0.46 | = | 0.920 | ||
Spinach | 50 | × | 0.54 | = | 0.270 | ||
Farina croquette | 276 | × | 0.76 | = | 2.098 | ||
Syrup | 100 | × | 0.024 | = | 0.024 | ||
Coffee | 100 | × | 0.06 | = | 0.060 | ||
Sugar | 14 | × | 0.00 | = | 0.000 | ||
Cream | 50 | × | 0.45 | = | 0.225 | ||
Total nitrogen in food | 10.424 | grams. | |||||
Total nitrogen in urine | 6.390 |
Fuel value of the food | 3229 calories. |
NITROGEN BALANCE.—Mendel.
Nitrogen Taken in. |
Output. | |||||||||
---|---|---|---|---|---|---|---|---|---|---|
Nitrogen in Urine. | Weight of Fæces (dry). | |||||||||
May | 18 | 8.668 | grams. | 6.06 | grams. | 14 | grams. | |||
19 | 6.474 | 7.17 | 39 | |||||||
20 | 6.691 | 6.33 | 30 | |||||||
21 | 8.345 | 6.78 | 83 | contain 6.06% N | = | 5.03 | grm. N. | |||
22 | 7.015 | 5.70 | ||||||||
23 | 9.726 | 5.75 | 38 | |||||||
24 | 10.424 | 6.39 | 57 | |||||||
95 | contain 5.76% N | = | 5.47 | grm. N. | ||||||
10.50 | grm. N. | |||||||||
57.343 | 44.18 | + | 10.50 | grams nitrogen. | ||||||
57.343 | grams nitrogen. | 54.68 | grams nitrogen. |
Nitrogen balance for seven days | = | +2.663 | grams. |
Nitrogen balance per day | = | +0.380 | gram. |
Average Intake.
Calories per day | 2448. |
Nitrogen per day | 8.192 grams. |
In this period of seven days the average daily intake of nitrogen was 8.192 grams, or only 0.36 gram per day more than in the first balance period, while the average fuel value of the food amounted to 2448 calories per day. Yet the average daily output of nitrogen through the urine for this period was 6.31 grams, or 1.2 grams per day less than in the first balance experiment. Further, under the conditions of this balance experiment, the body was laying up 0.380 gram of nitrogen per day, i. e., showing a plus balance of 2.66 grams of nitrogen for the seven days’ period. Again, it is to be noted that the average daily amount of nitrogen metabolized, 6.31 grams, was 0.22 gram less than the average daily nitrogen excretion for the entire seven months’ period, 6.53 grams. Evidently, this subject was quite able to maintain nitrogen equilibrium with a metabolism of only 6.31 grams of nitrogen per day, on a daily diet having a fuel value of about 2400 calories. Indeed, taking into account the amount of the plus nitrogen balance, it is evident that the daily food was somewhat in excess of the real requirements of the body, under the then existing conditions of body-weight and bodily activity.
Again, we would call attention to the thorough utilization of the food in this experiment, emphasizing at the same time the voluminous character of the diet, together with its largely vegetable nature. The contrast between the diet made use of by Dr. Mendel and that used by the subject of the first experiment is quite striking, since the latter employed a much more concentrated diet with an average fuel value of only 1600 calories. Yet with a total intake of 57.343 grams of nitrogen for the seven days of Dr. Mendel’s balance period, 10.5 grams only passed out through the rectum, or 18.3 per cent, while in the second nitrogen balance of the first subject, with the more concentrated diet, 17.1 per cent of the total ingested nitrogen appeared in the fæces. In view of the great divergence in the character and volume of the intake, it is rather remarkable there should be so little difference in the relative utilization of the two diets.
Finally, taking the average daily excretion of nitrogen through the kidneys from November 10 to June 23, as a measure of the nitrogen metabolized daily, viz., 6.53 grams, and taking the body-weight at 70 kilos, it is plain to see that the nitrogen metabolized per kilo of body-weight throughout this experiment was 0.093 gram, closely similar to the result obtained with the first subject. In other words, both of these subjects, though widely different in body-weight, under different degrees of physical activity, and living on different forms of diet, seemingly required for the maintenance of equilibrium essentially the same amount of nitrogen per kilo of body-weight; viz., with the first subject 0.0947 gram, if we take the lower figure of the last two months, and 0.093 gram with the second subject.
Regarding the fuel value of the daily food, Dr. Mendel with a body-weight of 70 kilos, during the second balance period, apparently utilized on an average 34.9 calories per kilo of body-weight daily, while the first subject, of 57 kilos body-weight, made use of only 28 calories per kilo. The fuel value of the daily food must, however, as is well known, vary greatly with differing degrees of physical activity, from which arises the necessity for corresponding variation in the amounts of non-nitrogenous foods ingested.
Dr. Frank P. Underhill, instructor in physiological chemistry in the Sheffield Scientific School, is another subject of experiment who volunteered to study on himself the effects of a lowered proteid intake. Prior to the experiment he was in the habit of eliminating from 16 to 16.5 grams of nitrogen per day through the kidneys, representing the usual 105 grams of proteid food metabolized.
Dr. Underhill, at the beginning of the experiment, July 1, 1903, was twenty-six years of age and weighed 67.6 kilos. For a period of two weeks, from July 14 to August 2, he gradually reduced the intake of proteid food as well as the total amount of food consumed, doing this in part by diminishing the quantity eaten at breakfast, and in smaller measure[77] at the two other meals of the day. During this period of two weeks, the urine and fæces were analyzed with the results shown in the accompanying table. Regarding the extent of proteid metabolism, it will be seen that the nitrogen content of the urine fell from 14.28 grams per day down to 5 to 6 grams per day. Having reached this level, the subject maintained it throughout the summer of 1903, occasional analyses being made to demonstrate the level of nitrogen excretion.
Date. | Body- weight. |
Urine. | Fæces. | Total Nitrogen. |
|||||
---|---|---|---|---|---|---|---|---|---|
Volume. | Sp. Gr. | Nitrogen. | Moist. | Dry. | Nitrogen. | ||||
1903. | c.c. | grams. | grams. | grams. | grams. | grams. | |||
July | 14 | 67.6 | 1300 | 1018 | 14.28 | 156.0 | 30.5 | 1.59 | 15.8 |
15 | 67.6 | 1095 | 1020 | 11.72 | 70.0 | 17.0 | 0.80 | 12.52 | |
16 | 67.1 | 860 | 1021 | 11.72 | 182.5 | 44.5 | 2.12 | 13.84 | |
17 | 66.9 | 675 | 1022 | 9.39 | 134.0 | 43.0 | 2.05 | 11.44 | |
18 | 66.3 | 865 | 1021 | 10.45 | 57.5 | 20.0 | 0.95 | 11.40 | |
19 | 65.7 | 785 | 1021 | 10.34 | 170.0 | 41.0 | 1.95 | 12.29 | |
20 | 65.7 | 740 | 1024 | 10.34 | 76.0 | 35.0 | 1.66 | 12.00 | |
21 | 65.7 | 910 | 1017 | 11.61 | 96.0 | 32.0 | 1.52 | 13.13 | |
22 | 65.7 | 900 | 1013 | 9.50 | 56.0 | 31.0 | 1.75 | 11.25 | |
23 | 65.3 | 600 | 1017 | 8.65 | 41.0 | 14.0 | 0.79 | 9.35 | |
24 | 65.0 | 640 | 1013 | 6.65 | 151.0 | 33.0 | 1.86 | 8.51 | |
25 | 65.3 | 690 | 1012 | 6.01 | 86.0 | 29.0 | 1.63 | 7.64 | |
26 | 65.3 | 410 | 1023 | 6.65 | 57.0 | 19.0 | 1.06 | 7.71 | |
27 | 65.7 | 530 | 1017 | 6.75 | 202.0 | 33.0 | 1.86 | 8.61 | |
28 | 65.7 | 610 | 1013 | 5.49 | 155.0 | 26.0 | 1.46 | 6.95 | |
29 | 66.4 | 620 | 1017 | 5.96 | 121.0 | 26.0 | 1.46 | 7.42 | |
30 | 66.3 | 700 | 1016 | 5.80 | 233.0 | 48.0 | 2.71 | 8.51 | |
31 | 65.8 | 1265 | 1010 | 6.70 | 211.0 | 36.0 | 2.03 | 8.73 | |
Aug. | 1 | 65.3 | 1240 | 1009 | 6.23 | 172.0 | 23.0 | 1.29 | 7.52 |
2 | 65.3 | 760 | 1016 | 6.75 | 214.0 | 27.0 | 1.42 | 8.17 | |
11 | 65.3 | 500 | 1017 | 6.44 | 152.0 | 22.0 | 1.34 | 7.78 | |
12 | 65.3 | 405 | 1024 | 6.86 | 70.0 | 15.0 | 0.91 | 7.77 | |
13 | 65.3 | 540 | 1019 | 6.23 | 90.0 | 10.0 | 0.61 | 6.84 |
In connection with the accompanying table of results, attention is called to the composition of the fæces with special reference to their content of nitrogen. The point to be emphasized is the gradual increase in the percentage content of fæcal nitrogen, associated with the changed diet and the general diminution of food intake. This is well illustrated by the following figures, giving the percentage of nitrogen in the dry fæces for the three periods of July 14-21, July 22-30, and August 11-13:
July 14-21, | 4.77 | per | cent | Nitrogen |
July 22-30, | 5.65 | ” | ” | ” |
Aug. 11-13, | 6.11 | ” | ” | ” |
The diminished amount of fæcal discharge means naturally not only a smaller intake of food, but implies also a greater utilization of the food ingested, and as a result the increased percentage of nitrogen in the discharges shows itself because of the relatively larger preponderance of nitrogenous secretions from the intestinal tract.
The latter part of September, 1903, Dr. Underhill attempted to return to his original methods of living, but found difficulty in consuming the daily quantities of food he had formerly been in the habit of taking. From October 11 to October 25, 1903, however, he raised the consumption of proteid food to such a degree that the nitrogen excretion through the urine averaged from 10 to 12 grams per day. After this date he fell back to the lower proteid intake, and from that period to June 23, 1904, he maintained a low level of proteid metabolism without detriment to his bodily vigor, and, as he believes, with a distinct betterment.
The following tables of results extending from October 11, 1903, to June 23, 1904, show the data collected.
It will be seen by a study of the analytical data that Dr. Underhill had an average daily excretion of nitrogen through the kidneys from October 26, 1903, to June 23, 1904, of 7.43 grams. From October 26 to April 13, a period of nearly six months, the average daily excretion was 7.81 grams of nitrogen, while from the latter date to June 23 the average daily excretion amounted to 6.68 grams of nitrogen. Taking the body-weight at 65 kilos, the lower nitrogen figure would mean a metabolism of 0.102 gram of nitrogen per kilo of body-weight, closely akin to the figures obtained with the two preceding subjects.
An excretion of 6.68 grams of nitrogen corresponds to the metabolism of 41.75 grams of proteid matter, while the excretion of 7.43 grams of nitrogen implies the metabolism of 46.4 grams of proteid, being less than one-half the ordinarily accepted requirement for the healthy adult.
During this long period of eight months the body-weight was stationary, carrying with it the assumption that the body was in a condition of nitrogen equilibrium. It should be emphasized in connection with Dr. Underhill’s case, that throughout the entire period of eight months, and more, there was perfect freedom in the choice of food. Further, it will be noticed by a study of the dietary made use of in the balance experiments that Dr. Underhill did not reduce his nitrogen intake by any exclusion of meat. He practically made use of his ordinary diet, such as he had always been accustomed to, but with a decided diminution of the amount of proteid food, accompanied by a gradual reduction in the total amount of food consumed each day. His diet, therefore, was in no sense a vegetable diet. Meat was conspicuous in his daily food, but naturally in reduced quantities.
On February 9 a nitrogen balance was attempted, in which a careful comparison of the nitrogen content of all intake and output was made for a period of six days. By a study of the results of this balance period, shown in the accompanying tables, it will be noticed that not only was there no deficiency of nitrogen, but the body was laying on nitrogen at the rate of 0.158 gram per day. Further, it will be observed that the fuel value of the food per day averaged only a little over 2000 calories. Yet this amount of food, with its comparatively low fuel value, carried with it only 8.83 grams of nitrogen per day. Upon this quantity of food the body was able to maintain itself, with a little nitrogen to spare and with sufficient fuel value in the food to supply all the energy required for muscular contraction, mental effort, and the maintenance of body temperature.
Tuesday, February 9, 1904.
Breakfast.—Bread 22 grams, tea 146 grams.
Lunch.—Macaroni 129 grams, fried sweet potato 85.5 grams, bread 59 grams, butter 15 grams, fig cake with wine sauce 115 grams, sugar 15 grams, coffee 210 grams.
Dinner.—Bread 27.9 grams, beef 48 grams, potato 207.5 grams, butter 19 grams, pie 272 grams, coffee 210 grams, sugar 10 grams.
Food. | Grams. | Per cent Nitrogen. | Total Nitrogen. | ||||
---|---|---|---|---|---|---|---|
Bread | 22 + 59 + 27.9 = | 108.9 | × | 1.61 | = | 1.753 | grams. |
Tea | 146.0 | × | 0.018 | = | 0.026 | ||
Macaroni | 129.0 | × | 0.87 | = | 1.122 | ||
Sweet potato | 85.5 | × | 0.28 | = | 0.240 | ||
Butter | 15 + 19 = | 34.0 | × | 0.088 | = | 0.030 | |
Fig cake | 115.0 | × | 0.69 | = | 0.793 | ||
Sugar | 15 + 10 = | 25.0 | × | 0.00 | = | 0.000 | |
Coffee (lunch) | 210.0 | × | 0.09 | = | 0.207 | ||
Beef | 48.0 | × | 2.64 | = | 1.267 | ||
Potatoes | 207.5 | × | 0.36 | = | 0.747 | ||
Pie | 272.0 | × | 0.49 | = | 1.332 | ||
Coffee (dinner) | 210.0 | × | 0.15 | = | 0.315 | ||
Total nitrogen in food | 7.832 | grams. | |||||
Total nitrogen in urine | 7.490 |
Fuel value of the food | 2232 calories. |
Wednesday, February 10, 1904.
Breakfast.—Bread 33 grams, tea 146 grams.
Lunch.—Bread 71 grams, butter 10.5 grams, apple fritters 119 grams, coffee 210 grams, sugar 21 grams.
Dinner.—Roast pork 80 grams, bread 55.7 grams, butter 27.8 grams, cranberry sauce 150 grams, coffee 210 grams, sugar 21 grams.
Fuel value of the food | 1694 calories. |
Thursday, February 11, 1904.
Breakfast.—Bread 38.7 grams, tea 146 grams.
Lunch.—Bread 97.5 grams, butter 31.5 grams, sweet potato 108.7 grams, spaghetti 82.5 grams, peaches 89.4 grams, coffee 210 grams, sugar 21 grams.
Dinner.—Bread 75 grams, butter 21.5 grams, roast beef 116 grams, lemon pie 188.5 grams, coffee 210 grams, sugar 21 grams.
Food. | Grams. | Per cent Nitrogen. | Total Nitrogen. | ||||
---|---|---|---|---|---|---|---|
Bread | 38.7 + 97.5 + 75 = | 211.2 | × | 1.75 | = | 3.696 | grams. |
Tea | 146.0 | × | 0.084 | = | 0.122 | ||
Butter | 31.5 + 21.5 = | 53.0 | × | 0.088 | = | 0.046 | |
Sweet potato | 108.7 | × | 0.31 | = | 0.336 | ||
Spaghetti | 82.5 | × | 0.47 | = | 0.387 | ||
Peaches | 89.4 | × | 0.09 | = | 0.080 | ||
Coffee (lunch) | 210.0 | × | 0.096 | = | 0.201 | ||
Sugar | 21 + 21 = | 42.0 | × | 0.00 | = | 0.000 | |
Roast beef | 116.0 | × | 3.00 | = | 3.480 | ||
Lemon pie | 188.5 | × | 0.61 | = | 1.149 | ||
Coffee (dinner) | 210.0 | × | 0.13 | = | 0.273 | ||
Total nitrogen in food | 9.770 | grams. | |||||
Total nitrogen in urine | 8.020 |
Fuel value of the food | 2334 calories. |
Friday, February 12, 1904.
Breakfast.—Bread 34 grams, tea 146 grams.
Lunch.—Bread 42 grams, butter 20 grams, codfish cake 72 grams, potato 100 grams, custard 100 grams, coffee 210 grams, sugar 21 grams.
Dinner.—Bread 46 grams, butter 25.5 grams, veal 53 grams, potato 75 grams, lima beans 50 grams, apple dumpling 120 grams, coffee 210 grams, sugar 21 grams.
Food. | Grams. | Per cent Nitrogen. | Total Nitrogen. | ||||
---|---|---|---|---|---|---|---|
Bread | 34 + 42 + 46 = | 122.0 | × | 1.71 | = | 2.086 | grams. |
Tea | 146.0 | × | 0.045 | = | 0.065 | ||
Butter | 20 + 25.5 = | 45.5 | × | 0.088 | = | 0.040 | |
Codfish cake | 72.0 | × | 1.57 | = | 1.130 | ||
Potato | 100.0 | × | 0.41 | = | 0.410 | ||
Custard | 100.0 | × | 0.83 | = | 0.830 | ||
Coffee (lunch) | 210.0 | × | 0.078 | = | 0.163 | ||
Sugar | 21 + 21 = | 42.0 | × | 0.00 | = | 0.000 | |
Veal | 53.0 | × | 5.51 | = | 2.920 | ||
Potato | 75.0 | × | 0.37 | = | 0.277 | ||
Lima beans | 50.0 | × | 0.90 | = | 0.450 | ||
Apple dumpling | 120.0 | × | 0.72 | = | 0.860 | ||
Coffee (dinner) | 210.0 | × | 0.12 | = | 0.252 | ||
Total nitrogen in food | 9.483 | grams. | |||||
Total nitrogen in urine | 8.820 |
Fuel value of the food | 1735 calories. |
Saturday, February 13, 1904.
Breakfast.—Bread 35 grams, tea 146 grams.
Lunch.—Bread 57.5 grams, butter 28 grams, sweet potato 100 grams, coffee 210 grams, sugar 21 grams, quince 105.5 grams, apple turnovers 153 grams.
Dinner.—Bread 35.5 grams, butter 11 grams, peas 70 grams, roast beef 50 grams, pie 169 grams, coffee 210 grams, sugar 21 grams.
Fuel value of the food | 2186 calories. |
Sunday, February 14, 1904.
Breakfast.—Bread 31 grams, tea 146 grams.
Lunch.—Bread 70.5 grams, butter 29 grams, potato 123 grams, apple sauce 127.5 grams, coffee 210 grams, sugar 21 grams.
Dinner.—Bread 20.5 grams, butter 23 grams, chicken 101.5 grams, potato 80 grams, succotash 80 grams, chocolate cake 103 grams, ice cream 125.8 grams, coffee 210 grams, sugar 21 grams.
Food. | Grams. | Per cent Nitrogen. | Total Nitrogen. | ||||
---|---|---|---|---|---|---|---|
Bread | 31 + 70.5 + 20.5 = | 122.0 | × | 1.75 | = | 2.135 | grams. |
Tea | 146.0 | × | 0.063 | = | 0.091 | ||
Butter | 29 + 23 = | 52.0 | × | 0.088 | = | 0.045 | |
Potato | 123.0 | × | 0.41 | = | 0.504 | ||
Apple sauce | 127.5 | × | 0.029 | = | 0.037 | ||
Coffee (lunch) | 210.0 | × | 0.10 | = | 0.210 | ||
Sugar | 21 + 21 = | 42.0 | × | 0.00 | = | 0.000 | |
Chicken | 101.5 | × | 5.08 | = | 5.150 | ||
Potato | 80.0 | × | 0.37 | = | 0.296 | ||
Succotash | 80.0 | × | 0.57 | = | 0.456 | ||
Chocolate cake | 103.0 | × | 0.75 | = | 0.772 | ||
Ice cream | 125.8 | × | 0.58 | = | 0.729 | ||
Coffee (dinner) | 210.0 | × | 0.11 | = | 0.231 | ||
Total nitrogen in food | 10.656 | grams. | |||||
Total nitrogen in urine | 7.730 |
Fuel value of the food | 2231 calories. |
NITROGEN BALANCE.—Underhill.
Nitrogen Taken in. |
Output. | ||||||
---|---|---|---|---|---|---|---|
Nitrogen in Urine. | Weight of Fæces (dry). | ||||||
Feb. | 9 | 7.832 | grams. | 7.49 | grams. | 9.5 | grams. |
10 | 7.674 | 6.14 | |||||
11 | 9.770 | 8.02 | 32.0 | ||||
12 | 9.483 | 8.82 | 9.5 | ||||
13 | 7.622 | 7.17 | 28.0 | ||||
14 | 10.656 | 7.73 | 24.0 | ||||
103.0 | grams contain 6.52% N. |
||||||
53.037 | 45.37 | + | 6.715 | grams nitrogen. | |||
53.037 | grams nitrogen. | 52.085 | grams nitrogen. |
Nitrogen balance for six days | = | +0.952 | gram. |
Nitrogen balance per day | = | +0.158 | gram. |
Average Intake.
Calories per day | 2068. |
Nitrogen per day | 8.83 grams. |
On June 1, near the close of the experiment, a second nitrogen balance was attempted, with a view to seeing if under the existing conditions of life and activity it was possible to reduce the fuel value of the food, and at the same time diminish in still greater measure the quantity of proteid food taken. The results of this trial are seen in the accompanying tables, where for four days a careful comparison of output and intake is shown. It will be observed from these tables that the average fuel value of the food per day was reduced to 1785 calories, and that the average intake of nitrogen was restricted to 6.73 grams per day. The balance shown is a minus balance, although the deficiency per diem is not large. It is very obvious that both the nitrogen and fuel value of the food can be reduced considerably below the average maintained during the period of the first balance, but not to the degree attempted in the second balance, and secure nitrogen or body equilibrium. It will be noted in this last nitrogen balance, that the average daily output of nitrogen through the urine amounted to 6.46 grams, while the average nitrogen intake was 6.73 grams. The fuel value of the food, however, averaged only 1785 calories per day. It is quite evident, if the non-nitrogenous food had not been reduced quite so much, that a plus nitrogen balance would have been obtained. Still, it is obvious that under the conditions of life and activity, this subject needed to metabolize only about 40 grams of proteid per day, with the total fuel value of his food equal to about 2000 calories, in order to secure both body and nitrogen equilibrium. Here, again, we have an illustration of the possibility of physiological economy which shows itself in a reduction of the daily proteid food more than 50 per cent, with a reduction of the non-nitrogenous food fully 30 per cent, and with maintenance of health, strength and vigor equal, if not superior, to that which the subject has ever experienced.
Wednesday, June 1, 1904.
Breakfast.—Champagne wafer 21.5 grams, tea 146 grams, sugar 15 grams.
Dinner.—Bread 67.4 grams, butter 15.1 grams, beefsteak 55.5 grams, potato 128 grams, asparagus 103.5 grams, tea 146 grams, sugar 15 grams, banana 83.5 grams.
Supper.—Bread 15.7 grams, butter 11.8 grams, banana and nuts 106 grams, crullers 90.2 grams, coffee 145 grams, sugar 15 grams.
Food. | Grams. | Per cent Nitrogen. | Total Nitrogen. | ||||
---|---|---|---|---|---|---|---|
Champagne wafer | 21.5 | × | 0.64 | = | 0.138 | gram. | |
Tea | 146.0 | × | 0.015 | = | 0.022 | ||
Sugar | 15 + 15 + 15 = | 45.0 | × | 0.000 | = | 0.000 | |
Bread | 67.4 + 15.7 = | 83.1 | × | 1.46 | = | 1.212 | |
Butter | 15.1 + 11.8 = | 26.9 | × | 0.10 | = | 0.027 | |
Banana | 83.5 | × | 0.28 | = | 0.192 | ||
Beefsteak | 55.5 | × | 4.72 | = | 2.620 | ||
Potato | 128.0 | × | 0.32 | = | 0.410 | ||
Asparagus | 103.5 | × | 0.35 | = | 0.362 | ||
Tea | 146.0 | × | 0.033 | = | 0.048 | ||
Crullers | 90.2 | × | 1.04 | = | 0.938 | ||
Banana and nuts | 106.0 | × | 0.69 | = | 0.731 | ||
Coffee | 145.0 | × | 0.060 | = | 0.087 | ||
Total nitrogen in food | 6.787 | grams. | |||||
Total nitrogen in urine | 5.960 |
Fuel value of the food | 1913 calories. |
Thursday, June 2, 1904.
Breakfast.—Bread 30 grams, tea 146 grams, sugar 15 grams.
Dinner.—Clam chowder 270.5 grams, bread 64 grams, butter 14.5 grams, lobster 36.5 grams, Saratoga chips 15 grams, caramel custard 79 grams, tea 146 grams, sugar 15 grams.
Supper.—Bread 35.2 grams, butter 13.8 grams, pineapple 148.7 grams, crullers 84.8 grams, tea 140 grams, sugar 15 grams.
Fuel value of the food | 1921 calories. |
Friday, June 3, 1904.
Breakfast.—Bread 31 grams, tea 146 grams.
Dinner.—Fried ham 61 grams, asparagus 124.2 grams, baked potato 85 grams, bread 29 grams, butter 23.5 grams, tea 140 grams, sugar 15 grams, pineapple 74.8 grams.
Supper.—Bread 34 grams, butter 17.8 grams, pineapple 158.5 grams, tomato 132.5 grams, cup cake 121 grams, tea 140 grams, sugar 15 grams.
Food. | Grams. | Per cent Nitrogen. | Total Nitrogen. | ||||
---|---|---|---|---|---|---|---|
Bread | 31 + 20 + 34 = | 94.0 | × | 1.44 | = | 1.354 | grams. |
Tea | 146.0 | × | 0.039 | = | 0.057 | ||
Fried ham | 61.0 | × | 4.90 | = | 2.989 | ||
Asparagus | 124.2 | × | 0.50 | = | 0.621 | ||
Baked potato | 85.0 | × | 0.55 | = | 0.468 | ||
Butter | 23.5 + 17.8 = | 41.3 | × | 0.10 | = | 0.041 | |
Tea | 140.0 | × | 0.027 | = | 0.038 | ||
Sugar | 15 + 15 = | 30.0 | × | 0.000 | = | 0.000 | |
Pineapple | 74.8 + 158.5 = | 233.3 | × | 0.065 | = | 0.152 | |
Tea | 140.0 | × | 0.054 | = | 0.076 | ||
Tomato | 132.5 | × | 0.150 | = | 0.199 | ||
Cup cake | 121.0 | × | 0.85 | = | 1.029 | ||
Total nitrogen in food | 7.024 | grams. | |||||
Total nitrogen in urine | 7.300 |
Fuel value of the food | 2011 calories. |
Saturday, June 4, 1904.
Breakfast.—Bread 32 grams, tea 140 grams.
Dinner.—Hash 133 grams, peas 151.5 grams, bread 61.4 grams, butter 16.1 grams, custard 150 grams, sugar 15 grams, tea 140 grams.
Supper.—Bread 62.5 grams, butter 17 grams, tea 140 grams, sugar 15 grams.
Food. | Grams. | Per cent Nitrogen. | Total Nitrogen. | ||||
---|---|---|---|---|---|---|---|
Bread | 32.0 | × | 1.44 | = | 0.461 | gram. | |
Tea | 140.0 | × | 0.021 | = | 0.029 | ||
Hash | 133.0 | × | 1.50 | = | 1.995 | ||
Peas | 151.5 | × | 1.04 | = | 1.576 | ||
Bread | 61.4 + 62.5 = | 123.9 | × | 1.47 | = | 1.821 | |
Butter | 16.1 + 17 = | 33.1 | × | 0.10 | = | 0.033 | |
Custard | 150.0 | × | 0.78 | = | 1.170 | ||
Sugar | 15 + 15 = | 30.0 | × | 0.00 | = | 0.000 | |
Tea | 140.0 | × | 0.033 | = | 0.046 | ||
Tea | 140.0 | × | 0.030 | = | 0.042 | ||
Total nitrogen in food | 7.173 | grams. | |||||
Total nitrogen in urine | 6.780 |
Fuel value of the food | 1297 calories. |
NITROGEN BALANCE.—Underhill.
Nitrogen Taken in. |
Output. | ||||||
---|---|---|---|---|---|---|---|
Nitrogen in Urine. | Weight of Fæces (dry). | ||||||
June | 1 | 6.787 | grams. | 5.96 | grams. | 10 | grams. |
2 | 6.060 | 5.81 | 10 | ||||
3 | 7.024 | 7.30 | 25 | ||||
4 | 7.173 | 6.78 | 6 | ||||
51 | grams contain 5.81 % N. |
||||||
27.044 | 25.85 | + | 2.963 | grams nitrogen. | |||
27.044 | grams nitrogen. | 28.813 | grams nitrogen. |
Nitrogen balance for four days | = | -1.760 | grams. |
Nitrogen balance per day | = | -0.442 | grams. |
Average Intake.
Calories per day | 1785. |
Nitrogen per day | 6.73 grams. |
Dr. Arthur L. Dean, Instructor in Plant Physiology in the Sheffield Scientific School, twenty-five years of age, and weighing 64 kilos, likewise became a subject of study in this investigation. He is a man of strong physique, and as an undergraduate student at Harvard University trained for various athletic events. He began on the experiment October 13, 1903, and continued until April 3, 1904. From October 13th to October 27 he followed his usual dietary habits, simply reducing in some measure the amount of food consumed. During this period of fifteen days, the average excretion of nitrogen per day through the kidneys was about 12 grams. On the 28th of October he began to reduce in still greater measure the amount of proteid food eaten, and gradually diminished the extent of his proteid metabolism, although not to the same degree as the preceding subjects. He had full freedom of choice in the character and quantity of his diet, but his food was characterized by a predominance of vegetable matter, with an almost complete exclusion of meat.
For a period of nearly six months, or more exactly, from October 28 to April 3, the average daily output of nitrogen through the kidneys amounted to 8.99 grams, while the average daily output of uric acid was 0.386 gram. This daily excretion of 8.99 grams of nitrogen implies a metabolism of 56.18 grams of proteid. This, to be sure, means a reduction in proteid metabolism of about 50 per cent, as compared with the Voit and other standards, but does not show an economy equal to that practised by the preceding subjects. It is to be noted, however, in Dr. Dean’s case, that the body-weight did not show at any time in the experiment a tendency to diminish. In fact, all through the experiment his body-weight was a little higher than at the beginning.
On February 9, a nitrogen balance was attempted, when for a period of six days a careful comparison of intake and output of nitrogen was made. The results show that while during this period of six days 52.999 grams of nitrogen were ingested, there was an output through the urine and fæces of 61.13 grams of nitrogen, thus indicating a minus balance for this period of 1.355 grams of nitrogen per day. The average daily intake of nitrogen was 8.83 grams. The average daily output of nitrogen through the kidneys was 8.77 grams, being 0.22 gram less than the average daily excretion through the kidneys for the six months’ period. The fuel value of the food for this period averaged 2529 calories per day. The nitrogen balance, however, is so strikingly a minus balance that we are forced to conclude the above quantities of food were not quite sufficient to meet the needs of the body under the then existing conditions. Still, the fact that the body-weight during the entire period of six months showed no tendency downward implies that during this longer period the body must have been essentially in nitrogen equilibrium, under conditions whereby there was a metabolism of only 56 grams of proteid per day. As before stated, this means a physiological economy, as contrasted with existing standards, of about 50 per cent in proteid[103] food. So far as was to be seen, the bodily strength and vigor of the subject, like his body-weight, were fully maintained under the restricted diet, but, for some reason, he did not apparently take as kindly to a reduction of proteid food, and did not accomplish so great a lowering in the rate of proteid metabolism.
Following are the data of the balance experiment:
Tuesday, February 9, 1904.
Breakfast.—Coffee 210 grams, bread 38.5 grams, oatmeal 127 grams, cream 92 grams, sugar 20 grams.
Lunch.—Bread 63.5 grams, butter 12.5 grams, potato 155 grams, consommé 150 grams, stewed tomato 109 grams, coffee 210 grams, sugar 20 grams, pudding 85 grams.
Dinner.—Roast beef 17.5 grams, potato 177 grams, bread 39.1 grams, butter 12 grams, string beans 110 grams, apple pie 237.6 grams.
Food. | Grams. | Per cent Nitrogen. | Total Nitrogen. | ||||
---|---|---|---|---|---|---|---|
Coffee | 210.0 | × | 0.10 | = | 0.210 | grams. | |
Bread | 38.5 + 63.5 + 39.1 = | 141.1 | × | 1.36 | = | 1.918 | |
Oatmeal | 127.0 | × | 0.64 | = | 0.812 | ||
Cream | 92.0 | × | 0.40 | = | 0.368 | ||
Butter | 12.5 + 12 = | 24.5 | × | 0.088 | = | 0.021 | |
Potato | 155.0 | × | 0.28 | = | 0.434 | ||
Consommé | 150.0 | × | 0.38 | = | 0.570 | ||
Tomato | 109.0 | × | 0.19 | = | 0.207 | ||
Sugar | 20 + 20 = | 40.0 | × | 0.00 | = | 0.000 | |
Pudding | 85.0 | × | 0.69 | = | 0.586 | ||
Roast beef | 17.5 | × | 2.64 | = | 0.462 | ||
Potato | 177.0 | × | 0.36 | = | 0.637 | ||
String beans | 110.0 | × | 0.26 | = | 0.286 | ||
Apple pie | 237.6 | × | 0.49 | = | 1.164 | ||
Coffee | 210.0 | × | 0.099 | = | 0.208 | ||
Total nitrogen in food | 7.883 | grams. | |||||
Total nitrogen in urine | 8.640 |
Fuel value of the food | 2576 calories. |
Wednesday, February 10, 1904.
Breakfast.—Coffee 210 grams, bread 31.8 grams, cream 50 grams, sugar 40 grams, oatmeal 155 grams.
Lunch.—Bread 77 grams, butter 14.5 grams, apple fritters 193.5 grams, coffee 210 grams, sugar 20 grams.
Dinner.—Bread 82 grams, butter 20 grams, cranberries 150 grams, baked beans 150 grams, coffee 210 grams, sugar 32 grams.
Food. | Grams. | Per cent Nitrogen. | Total Nitrogen. | ||||
---|---|---|---|---|---|---|---|
Coffee | 210.0 | × | 0.12 | = | 0.252 | grams. | |
Bread | 31.8 + 77 + 82 = | 190.8 | × | 1.65 | = | 3.148 | |
Cream | 50.0 | × | 0.47 | = | 0.235 | ||
Sugar | 40 + 20 + 32 = | 92.0 | × | 0.00 | = | 0.000 | |
Oatmeal | 155.0 | × | 0.60 | = | 0.930 | ||
Butter | 14.5 + 20 = | 34.5 | × | 0.088 | = | 0.030 | |
Fritters | 193.5 | × | 0.45 | = | 0.870 | ||
Coffee | 210.0 | × | 0.11 | = | 0.231 | ||
Cranberries | 150.0 | × | 0.04 | = | 0.060 | ||
Baked beans | 150.0 | × | 1.40 | = | 2.100 | ||
Coffee | 210.0 | × | 0.11 | = | 0.231 | ||
Total nitrogen in food | 8.087 | grams. | |||||
Total nitrogen in urine | 8.290 |
Fuel value of the food | 2145 calories. |
Thursday, February 11, 1904.
Breakfast.—Bread 49 grams, oatmeal 185.7 grams, cream 64 grams, coffee 210 grams, sugar 35 grams.
Lunch.—Bread 111.8 grams, butter 40.5 grams, sweet potato 287 grams, peach preserve 109.3 grams.
Dinner.—Tomato purée 99 grams, bread 94.5 grams, butter 21.5 grams, beans 138 grams, lemon pie 155 grams, coffee 210 grams, sugar 21 grams.
Fuel value of the food | 2854 calories. |
Friday, February 12, 1904.
Breakfast.—Oatmeal 192.3 grams, cream 75.5 grams, bread 41.6 grams, coffee 210 grams, sugar 20 grams.
Lunch.—Bread 64.1 grams, butter 14 grams, fish cakes 60 grams, potato 200 grams, custard 107.3 grams.
Dinner.—Bread 60 grams, butter 15 grams, lima beans 100 grams, potato 150 grams, apple dumpling 259 grams.
Food. | Grams. | Per cent Nitrogen. | Total Nitrogen. | ||||
---|---|---|---|---|---|---|---|
Oatmeal | 192.3 | × | 0.52 | = | 0.999 | grams. | |
Cream | 75.5 | × | 0.50 | = | 0.377 | ||
Bread | 41.6 + 64.1 + 60 = | 165.7 | × | 1.71 | = | 2.833 | |
Coffee | 210.0 | × | 0.11 | = | 0.231 | ||
Sugar | 20.0 | × | 0.00 | = | 0.000 | ||
Butter | 14 + 15 = | 29.0 | × | 0.088 | = | 0.025 | |
Fish cakes | 60.0 | × | 1.57 | = | 0.942 | ||
Potato | 200.0 | × | 0.41 | = | 0.820 | ||
Custard | 107.3 | × | 0.83 | = | 0.890 | ||
Lima beans | 100.0 | × | 0.90 | = | 0.900 | ||
Potato | 150.0 | × | 0.37 | = | 0.555 | ||
Apple dumpling | 259.0 | × | 0.72 | = | 1.864 | ||
Total nitrogen in food | 10.436 | grams. | |||||
Total nitrogen in urine | 9.930 |
Fuel value of the food | 2363 calories. |
Saturday, February 13, 1904.
Breakfast.—Oatmeal 150 grams, cream 42 grams, sugar 31 grams, bread 31 grams, coffee 210 grams.
Lunch.—Bread 36 grams, sweet potato 222 grams, butter 17 grams, quince preserve 81.5 grams, apple turnover 154.5 grains.
Dinner.—Potato 175 grams, bread 62 grams, butter 15 grams, peas 100 grams, apple pie 177 grams, coffee 210 grams, sugar 21 grams.
Food. | Grams. | Per cent Nitrogen. | Total Nitrogen. | ||||
---|---|---|---|---|---|---|---|
Oatmeal | 150.0 | × | 0.43 | = | 0.645 | grams. | |
Cream | 42.0 | × | 0.50 | = | 0.210 | ||
Sugar | 31 + 21 = | 52.0 | × | 0.00 | = | 0.000 | |
Bread | 31 + 36 + 62 = | 129.0 | × | 1.64 | = | 2.115 | |
Coffee | 210.0 | × | 0.11 | = | 0.231 | ||
Sweet potato | 222.0 | × | 0.37 | = | 0.821 | ||
Butter | 17 + 15 = | 32.0 | × | 0.088 | = | 0.028 | |
Quince preserve | 81.5 | × | 0.047 | = | 0.038 | ||
Apple turnover | 154.5 | × | 0.96 | = | 1.483 | ||
Potato | 175.0 | × | 0.37 | = | 0.647 | ||
Peas | 100.0 | × | 0.96 | = | 0.960 | ||
Apple pie | 177.0 | × | 0.43 | = | 0.761 | ||
Coffee | 210.0 | × | 0.11 | = | 0.231 | ||
Total nitrogen in food | 8.170 | grams. | |||||
Total nitrogen in urine | 8.870 |
Fuel value of the food | 2606 calories. |
Sunday, February 14, 1904.
Breakfast.—Quaker oats 150 grams, bread 42.5 grams, coffee 210 grams, sugar 31 grams, banana 88.2 grams, cream 87.6 grams.
Lunch.—Bread 87.3 grams, butter 28.7 grams, potato 210 grams, apple sauce 116.5 grams.
Dinner.—Bread 51.5 grams, butter 12.2 grams, sugar 21 grams, potato 150 grams, succotash 100 grams, chocolate cake 122.5 grams, vanilla ice 110.7 grams.
Food. | Grams. | Per cent Nitrogen. | Total Nitrogen. | ||||
---|---|---|---|---|---|---|---|
Quaker oats | 150.0 | × | 0.46 | = | 0.690 | grams. | |
Bread | 42.5 + 87.3 + 51.5 = | 181.3 | × | 1.75 | = | 3.172 | |
Coffee | 210.0 | × | 0.11 | = | 0.231 | ||
Sugar | 31 + 21 = | 52.0 | × | 0.00 | = | 0.000 | |
Banana | 88.2 | × | 0.20 | = | 0.176 | ||
Cream | 87.6 | × | 0.50 | = | 0.438 | ||
Butter | 28.7 + 12.2 = | 40.9 | × | 0.088 | = | 0.035 | |
Potato | 210.0 | × | 0.41 | = | 0.861 | ||
Apple sauce | 116.5 | × | 0.029 | = | 0.033 | ||
Potato | 150.0 | × | 0.37 | = | 0.555 | ||
Succotash | 100.0 | × | 0.57 | = | 0.570 | ||
Chocolate cake | 122.5 | × | 0.75 | = | 0.918 | ||
Vanilla ice | 110.7 | × | 0.58 | = | 0.642 | ||
Total nitrogen in food | 8.321 | grams. | |||||
Total nitrogen in urine | 8.330 |
Fuel value of the food | 2635 calories. |
NITROGEN BALANCE.—Dean.
Nitrogen Taken in. |
Output. | ||||||
---|---|---|---|---|---|---|---|
Nitrogen in Urine. | Weight of Fæces (dry). | ||||||
Feb. | 9 | 7.883 | grams. | 8.64 | grams. | ||
10 | 8.087 | 8.29 | |||||
11 | 10.102 | 8.55 | 18 | grams. | |||
12 | 10.436 | 9.93 | 18 | ||||
13 | 8.170 | 8.87 | 80 | ||||
14 | 8.321 | 8.33 | 58 | ||||
174 | grams contain 4.90% N. |
||||||
52.999 | 52.61 | + | 8.52 | grams nitrogen. | |||
52.999 | grams nitrogen. | 61.13 | grams nitrogen. |
Nitrogen balance for six days | = | -8.131 | grams. |
Nitrogen balance per day | = | -1.355 | grams. |
Average Intake.
Calories per day | 2529. |
Nitrogen per day | 8.83 grams. |
Mr. George M. Beers, Clerk in the Treasurer’s office of the Sheffield Scientific School, became a subject of study in January, 1903. Mr. Beers was thirty-eight years of age, and had always enjoyed fairly good health, although of somewhat frail physique. His occupation has always been indoor work as accountant, etc. His body-weight was 61 kilos.
Mr. Beers came to the writer for advice as to possible ways of improving his general health, and when it was learned that he was in the habit of eating large amounts of meat, the suggestion was made to him that it might be wise to ascertain the effect of a diminished quantity of proteid food, and as a result of this advice Mr. Beers began to cut down the amount of meat consumed daily. The effect of this abstention from meat was so noticeable that voluntarily all meat was withdrawn from his diet. With this change in dietary habits there came about a loss of body-weight, which, however, was soon regained.
Commencing with May 14, 1903, the amount of nitrogen excreted from the kidneys was determined from time to time, but not each day, since it was very soon found that Mr. Beers showed great regularity in his dietary habits, and a corresponding regularity in the composition of the output. This regularity was due in large measure to the fact that the subject became, for the time at least, practically a vegetarian. The beneficial effects noted in his own experience with abstention from meat led to his voluntarily excluding it from his daily diet, so that from January, 1903, to June, 1904, the subject practically tasted meat, fish, or eggs on only four occasions, namely, the 26th day of November, 1903, May 19, 20, and 21, 1904. With this limitation to a vegetable diet and with regular methods of living, the nitrogenous waste material was found to be constant within very narrow limits. Emphasis, however, should be laid upon the fact that there was no prescription of diet, but perfect freedom of choice, although this choice was limited wholly to vegetable and cereal foods.
The accompanying tables give the output of nitrogen, uric acid, etc., through the kidneys for various dates between May[110] 14, 1903, and June 15, 1904. Scrutiny of these tables shows that the average daily output of nitrogen, so far as the data show, amounted to 8.58 grams. This indicates an average daily metabolism of 53.62 grams of proteid material.
Likewise noticeable is the perfectly steady body-weight throughout this whole period of time, while the low level of 8.5 grams of metabolized nitrogen testifies to an economy in the use of proteid food, which indicates that in this subject at least the needs of the body for proteid food could easily be met by an amount equal to about one-half that called for by the Voit and similar standard dietaries.
Date. | Body-weight. | Urine. | ||||||||
---|---|---|---|---|---|---|---|---|---|---|
Volume. 24 hours. | Sp. Gr. | Nitrogen. | Uric Acid. | P₂O₅. | ||||||
1904 | kilos | c.c. | grams | gram | grams | |||||
May | 14 | 61.1 | 940 | 1020 | 8.23 | 0.330 | 1.82 | |||
Oct. | 8 | 920 | 1014 | 6.40 | 0.374 | 1.47 | ||||
13 | 61.1 | 740 | 1026 | 8.74 | 0.375 | 1.61 | ||||
14 | 780 | 1024 | 8.37 | |||||||
15 | 970 | 1018 | 8.90 | 0.374 | 1.04 | |||||
16 | 1365 | 1014 | 9.09 | |||||||
17 | 1295 | 1013 | 8.86 | |||||||
18 | 1400 | 1013 | 7.56 | 0.347 | 1.57 | |||||
20 | 61.1 | 1304 | 1014 | 8.14 | 0.328 | 1.44 | ||||
21 | 1510 | 1012 | 7.97 | |||||||
22 | 1450 | 1012 | 8.26 | 0.338 | 1.95 | |||||
23 | 1130 | 1013 | 7.86 | |||||||
24 | 1060 | 1019 | 8.46 | |||||||
25 | 1275 | 1015 | 8.25 | 0.375 | 1.74 | |||||
26 | 1390 | 1014 | 7.34 | |||||||
27 | 61.4 | 1000 | 1020 | 7.50 | 0.344 | 1.38 | ||||
Nov. | 21 | 61.4 | 670 | 1025 | 8.72 | |||||
22 | 925 | 1017 | 8.21 | 0.335 | 1.28 | |||||
23 | 585 | 1027 | 8.36 | |||||||
24 | 885 | 1023 | 8.02 | 0.354 | ||||||
25 | 800 | 1026 | 7.92 | |||||||
26 | 1095 | 1020 | 10.77* | 0.364 | 1.53 | |||||
Jan. | 5 | 61.4 | 1110 | 1018 | 8.99 | 0.324 | ||||
7 | 650 | 1024 | 8.15 | 0.278 | 1.29 | |||||
8 | 710 | 1020 | 7.88 | |||||||
9 | 910 | 1023 | 8.73 | |||||||
10 | 890 | 1020 | 8.01 | 0.327 | 1.21 | |||||
11 | 875 | 1017 | 7.51 | |||||||
12 | 480 | 1029 | 6.77 | |||||||
13 | 580 | 1023 | 8.00 | 0.398 | ||||||
14 | 765 | 1022 | 8.35 | |||||||
15 | 1360 | 1017 | 9.22 | |||||||
16 | 61.4 | 990 | 1020 | 8.79 | ||||||
17 | 835 | 1024 | 8.47 | 0.354 | ||||||
18 | 780 | 1020 | 8.05 | |||||||
19 | 790 | 1022 | 8.10 | 0.382 | ||||||
Feb. | 9 | 860 | 1023 | 8.46 | 0.355 | |||||
[112] | 10 | 61.4 | 850 | 1024 | 8.57 | 0.226 | ||||
11 | 61.4 | 750 | 1022 | 8.55 | 0.352 | |||||
12 | 61.4 | 595 | 1026 | 8.46 | 0.368 | |||||
13 | 61.4 | 640 | 1027 | 8.75 | 0.425 | |||||
14 | 60.8 | 730 | 1025 | 8.28 | 0.353 | |||||
Apr. | 18 | 61.5 | 610 | 1025 | 7.69 | ⎫ | 0.365 daily average |
|||
19 | 61.5 | 870 | 1020 | 9.87 | ⎪ | |||||
20 | 61.5 | 985 | 1019 | 8.87 | ⎪ | |||||
21 | 61.5 | 795 | 1024 | 8.25 | ⎬ | |||||
22 | 61.5 | 1090 | 1019 | 9.02 | ⎪ | |||||
23 | 61.5 | 970 | 1022 | 8.44 | ⎪ | |||||
24 | 61.5 | 810 | 1021 | 7.30 | ⎭ | |||||
25 | 61.5 | 850 | 1018 | 6.94 | ⎫ | 0.691 | ||||
26 | 61.5 | 620 | 1024 | 7.11 | ⎪ | |||||
28 | 450 | 1027 | 8.58 | ⎬ | ||||||
29 | 650 | 1025 | 9.52 | ⎪ | ||||||
30 | 1260 | 1018 | 10.20 | ⎪ | ||||||
May | 1 | 1060 | 1017 | 8.71 | ⎭ | |||||
2 | 610 | 1025 | 8.16 | |||||||
3 | 650 | 1022 | 8.70 | |||||||
4 | 61.5 | 870 | 1019 | 8.51 | ||||||
5 | 61.3 | 610 | 1025 | 8.31 | ||||||
6 | 61.3 | 655 | 1026 | 8.72 | ⎫ | 0.356 | ||||
7 | 680 | 1025 | 8.53 | ⎪ | ||||||
8 | 60.8 | 490 | 1026 | 7.00 | ⎪ | |||||
9 | 61.3 | 550 | 1026 | 7.59 | ⎬ | |||||
10 | 705 | 1025 | 7.78 | ⎪ | ||||||
11 | 730 | 1025 | 8.28 | ⎪ | ||||||
12 | 800 | 1025 | 9.36 | ⎭ | ||||||
16 | 715 | 1022 | 7.29 | |||||||
17 | 990 | 1018 | 6.95 | |||||||
18 | 715 | 1026 | 7.81 | |||||||
19 | 845 | 1926 | 10.45† | |||||||
20 | 61.5 | 1170 | 1020 | 11.02† | ||||||
21 | 61.2 | 795 | 1025 | 10.02† | ||||||
22 | 835 | 1020 | 8.42 | |||||||
23 | 695 | 1025 | 9.42 | |||||||
24 | 660 | 1025 | 9.82 | |||||||
[113] | 25 | 700 | 1025 | 9.91 | ⎫ | 0.434 | ||||
26 | 620 | 1026 | 8.59 | ⎪ | ||||||
27 | 665 | 1026 | 9.53 | ⎬ | ||||||
28 | 61.2 | 960 | 1021 | 10.31 | ⎪ | |||||
29 | 790 | 1023 | 9.24 | ⎭ | ||||||
31 | 930 | 1025 | 10.44 | |||||||
June | 1 | 855 | 1018 | 8.76 | ||||||
2 | 850 | 1023 | 8.01 | |||||||
3 | 860 | 1020 | 9.24 | |||||||
4 | 61.4 | 1145 | 1021 | 10.17 | ||||||
5 | 590 | 1024 | 7.47 | |||||||
6 | 510 | 1029 | 7.53 | |||||||
7 | 620 | 1027 | 8.26 | |||||||
8 | 985 | 1020 | 8.45 | |||||||
9 | 1220 | 1020 | 8.49 | |||||||
10 | 1220 | 1017 | 8.28 | |||||||
11 | 1710 | 1013 | 8.82 | |||||||
12 | 925 | 1017 | 7.11 | |||||||
13 | 920 | 1020 | 8.01 | |||||||
14 | 1090 | 1015 | 8.64 | |||||||
15 | 61.5 | 915 | 1022 | 8.68 | ||||||
Daily average | 880 | 1021 | 8.58 | 0.365 | 1.49 |
On February 9, a nitrogen balance was attempted covering a period of six days, in which there was an exact comparison of the nitrogen income and output. In this balance period it will be observed that the total amount of nitrogen taken in for the six days was 53.108 grams, while the output of nitrogen through the kidneys amounted to 51.07 grams. The nitrogen excreted through the fæces, however, brought the total nitrogen output up to 58.83 grams, thus making a minus balance for the six days of 5.722 grams of nitrogen. During this period the average fuel value of the food per day was 2168 calories. The average daily output of metabolized[114] nitrogen during the period was 8.5 grams, practically identical with the average daily excretion of nitrogen through the kidneys for the entire year, so far as determined. We have here a distinct minus balance, due either to an insufficient amount of proteid food, or an insufficient fuel value.
Tuesday, February 9, 1904.
Breakfast.—Oatmeal 237.5 grams, butter 10 grams, sugar 35 grams, milk 60 grams, coffee 210 grams.
Lunch.—Macaroni 142 grams, cheese 10.5 grams, bread 71.5 grams, sweet potato 119.5 grams, milk 250 grams.
Dinner.—Bread 80.7 grams, butter 20 grams, mashed potato 176 grams, string beans 77.5 grams, apple pie 82 grams, milk 250 grams.
Food. | Grams. | Per cent Nitrogen. | Total Nitrogen. | ||||
---|---|---|---|---|---|---|---|
Oatmeal | 237.5 | × | 0.64 | = | 1.520 | grams. | |
Butter | 10 + 20 = | 30.0 | × | 0.088 | = | 0.026 | |
Sugar | 35.0 | × | 0.00 | = | 0.000 | ||
Milk | 60 + 250 + 250 = | 560.0 | × | 0.52 | = | 2.912 | |
Coffee | 210.0 | × | 0.10 | = | 0.210 | ||
Macaroni | 142.0 | × | 0.87 | = | 1.235 | ||
Cheese | 10.5 | × | 4.45 | = | 0.467 | ||
Bread | 71.5 + 80.7 = | 152.2 | × | 1.36 | = | 2.069 | |
Sweet potato | 119.5 | × | 0.28 | = | 0.334 | ||
Mashed potato | 176.0 | × | 0.36 | = | 0.633 | ||
String beans | 77.5 | × | 0.26 | = | 0.201 | ||
Apple pie | 82.0 | × | 0.49 | = | 0.401 | ||
Total nitrogen in food | 10.008 | grams. | |||||
Total nitrogen in urine | 8.460 |
Fuel value of the food | 2094 calories. |
Wednesday, February 10, 1904.
Breakfast.—Oatmeal 299 grams, butter 19 grams, cream 71 grams, sugar 41 grams, coffee 210 grams.
Lunch.—Bread 79 grams, butter 11 grams, boiled potato 155.2 grams, milk 250 grams.
Dinner.—Bread 56 grams, butter 12 grams, baked beans 100 grams, cranberry sauce 150 grams, sugar 21 grams, coffee 210 grams.
Food. | Grams. | Per cent Nitrogen. | Total Nitrogen. | ||||
---|---|---|---|---|---|---|---|
Oatmeal | 99.0 | × | 0.60 | = | 1.794 | grams. | |
Butter | 19 + 11 + 12 = | 42.0 | × | 0.088 | = | 0.036 | |
Cream | 71.0 | × | 0.47 | = | 0.333 | ||
Sugar | 41 + 21 = | 62.0 | × | 0.00 | = | 0.000 | |
Coffee (breakfast) | 210.0 | × | 0.12 | = | 0.252 | ||
Bread | 79 + 56 = | 135.0 | × | 1.65 | = | 2.227 | |
Boiled potato | 155.2 | × | 0.39 | = | 0.605 | ||
Milk | 250.0 | × | 0.55 | = | 1.375 | ||
Baked beans | 100.0 | × | 1.40 | = | 1.400 | ||
Cranberry sauce | 150.0 | × | 0.04 | = | 0.060 | ||
Coffee (dinner) | 210.0 | × | 0.11 | = | 0.231 | ||
Total nitrogen in food | 8.313 | grams. | |||||
Total nitrogen in urine | 8.570 |
Fuel value of the food | 1723 calories. |
Thursday, February 11, 1904.
Breakfast.—Oatmeal 300 grams, cream 71 grams, butter 10 grams, sugar 41 grams, coffee 210 grams.
Lunch.—Butter 14 grams, bread 126 grams, boiled sweet potato 205 grams, milk 250 grams.
Dinner.—Bread 22 grams, butter 7.5 grams, mashed potato 100 grams, sugar 14 grams, milk 250 grams.
Fuel value of the food | 1979 calories. |
Friday, February 12, 1904.
Breakfast.—Oatmeal 300 grams, butter 10 grams, cream 74 grams, sugar 41 grams, coffee 210 grams.
Lunch.—Bread 86 grams, butter 9 grams, potato 200 grams, sugar 14 grams, milk 250 grams.
Dinner.—Bread 63 grams, butter 14 grams, mashed potato 150 grams, apple dumpling 136 grams, milk 250 grams.
Food. | Grams. | Per cent Nitrogen. | Total Nitrogen. | ||||
---|---|---|---|---|---|---|---|
Oatmeal | 300 | × | 0.52 | = | 1.560 | grams. | |
Butter | 10 + 9 + 14 = | 33 | × | 0.088 | = | 0.029 | |
Cream | 74 | × | 0.50 | = | 0.370 | ||
Sugar | 41 + 14 = | 55 | × | 0.00 | = | 0.000 | |
Coffee | 210 | × | 0.11 | = | 0.231 | ||
Bread | 86 + 63 = | 149 | × | 1.71 | = | 2.547 | |
Potato | 200 | × | 0.41 | = | 0.820 | ||
Milk | 250 + 250 = | 500 | × | 0.48 | = | 2.400 | |
Mashed potato | 150 | × | 0.37 | = | 0.555 | ||
Apple dumpling | 136 | × | 0.72 | = | 0.979 | ||
Total nitrogen in food | 9.491 | grams. | |||||
Total nitrogen in urine | 8.460 |
Fuel value of the food | 2209 calories. |
Saturday, February 13, 1904.
Breakfast.—Oatmeal 300 grams, butter 12 grams, cream 70 grams, sugar 41 grams, coffee 210 grams.
Lunch.—Bread 80 grams, butter 11 grams, sweet potato 132 grams, sugar 20 grams, milk 250 grams.
Dinner.—Bread 59.5 grams, mashed potato 175 grams, butter 11 grams, sugar 20 grams, apple pie 141 grams, milk 250 grams.
Food. | Grams. | Per cent Nitrogen. | Total Nitrogen. | ||||
---|---|---|---|---|---|---|---|
Oatmeal | 300.0 | × | 0.43 | = | 1.290 | grams. | |
Butter | 12 + 11 + 11 = | 34.0 | × | 0.088 | = | 0.029 | |
Cream | 70.0 | × | 0.50 | = | 0.350 | ||
Sugar | 41 + 20 + 20 = | 81.0 | × | 0.00 | = | 0.000 | |
Coffee | 210.0 | × | 0.11 | = | 0.231 | ||
Bread | 80 + 59.5 = | 139.5 | × | 1.64 | = | 2.287 | |
Sweet potato | 132.0 | × | 0.37 | = | 0.488 | ||
Milk | 250 + 250 = | 500.0 | × | 0.54 | = | 2.700 | |
Mashed potato | 175.0 | × | 0.37 | = | 0.647 | ||
Apple pie | 141.0 | × | 0.43 | = | 0.606 | ||
Total nitrogen in food | 8.628 | grams. | |||||
Total nitrogen in urine | 8.750 |
Fuel value of the food | 2395 calories. |
Sunday, February 14, 1904.
Breakfast.—Oatmeal 300 grams, butter 16 grams, cream 70 grams, sugar 41 grams, coffee 210 grams.
Lunch.—Baked potato 171 grams, bread 72 grams, butter 15 grams, sugar 21 grams, apple sauce 38 grams, milk 250 grams.
Dinner.—Bread 35.5 grams, butter 13.5 grams, mashed potato 180 grams, sugar 20 grams, chocolate cake 111 grams, ice cream 115 grams, milk 250 grams.
Food. | Grams. | Per cent Nitrogen. | Total Nitrogen. | ||||
---|---|---|---|---|---|---|---|
Oatmeal | 300.0 | × | 0.46 | = | 1.380 | grams. | |
Butter | 16 + 15 + 13.5 = | 44.5 | × | 0.088 | = | 0.039 | |
Cream | 70.0 | × | 0.50 | = | 0.350 | ||
Sugar | 41 + 21 + 20 = | 82.0 | × | 0.00 | = | 0.000 | |
Coffee | 210.0 | × | 0.11 | = | 0.231 | ||
Baked potato | 171.0 | × | 0.41 | = | 0.701 | ||
Bread | 72 + 35.5 = | 107.5 | × | 1.75 | = | 1.881 | |
Apple sauce | 38.0 | × | 0.029 | = | 0.011 | ||
Milk | 250 + 250 = | 500.0 | × | 0.40 | = | 2.000 | |
Mashed potato | 180.0 | × | 0.37 | = | 0.666 | ||
Chocolate cake | 111.0 | × | 0.75 | = | 0.832 | ||
Ice cream | 115.0 | × | 0.58 | = | 0.667 | ||
Total nitrogen in food | 8.758 | grams. | |||||
Total nitrogen in urine | 8.280 |
Fuel value of the food | 2610 calories. |
NITROGEN BALANCE.—Beers.
Nitrogen Taken in. |
Output. | ||||||
---|---|---|---|---|---|---|---|
Nitrogen in Urine. | Weight of Fæces (dry). | ||||||
Feb. | 9 | 10.008 | grams. | 8.46 | grams. | ||
10 | 8.313 | 8.57 | 44.7 | grams. | |||
11 | 7.910 | 8.55 | 19.0 | ||||
12 | 9.491 | 8.46 | 30.0 | ||||
13 | 8.628 | 8.75 | 28.0 | ||||
14 | 8.758 | 8.28 | 5.0 | ||||
126.7 | grams contain 6.13% N. |
||||||
53.108 | 51.07 | + | 7.76 | grams nitrogen. | |||
53.108 | grams nitrogen. | 58.83 | grams nitrogen. |
Nitrogen balance for six days | = | -5.722 | grams. |
Nitrogen balance per day | = | -0.953 | gram. |
Average Intake.
Calories per day | 2168. |
Nitrogen per day | 8.85 grams. |
On May 6, a second nitrogen balance was attempted covering a period of seven days, in which, as before, there was an exact comparison of the income and output of nitrogen. In this period of seven days, as shown in the accompanying tables, the fuel value of the food was essentially the same as in the preceding period, but the amount of proteid food was increased to an average intake of 10.10 grams per day. Under these conditions there was a distinct plus balance for the seven days amounting to 2.425 grams, thus showing that with this quantity of nitrogenous food the body was laying on nitrogen to the extent of 0.346 gram per day. The average daily amount of nitrogen metabolized during this period was only 8.18 grams, being quite noticeably below the average daily amount for the year. In other words, the results of this balance period show that with a consumption of food sufficient to yield about 2200 calories per day, the body of this subject needed to metabolize only 8.25 grams of nitrogen per day to more than maintain nitrogen equilibrium. Following are the tables of results:
Friday, May 6, 1904.
Breakfast.—Oatmeal 345 grams, butter 7 grams, sugar 30 grams, milk 100 grams, coffee 180 grams.
Dinner.—Bread 67 grams, potato 71 grams, corn 179 grams, pie 133 grams, milk 200 grams.
Supper.—Biscuit 75 grams, butter 11 grams, potato 106 grams, cake 52 grams, apricots 75 grams, milk 230 grams.
Food. | Grams. | Per cent Nitrogen. | Total Nitrogen. | ||||
---|---|---|---|---|---|---|---|
Oatmeal | 345 | × | 0.40 | = | 1.380 | grams. | |
Butter | 7 + 11 = | 18 | × | 0.11 | = | 0.020 | |
Sugar | 30 | × | 0.00 | = | 0.000 | ||
Milk | 100 + 200 + 230 = | 530 | × | 0.54 | = | 2.862 | |
Coffee | 180 | × | 0.14 | = | 0.252 | ||
Bread | 67 | × | 1.39 | = | 0.931 | ||
Potato (dinner) | 71 | × | 0.52 | = | 0.369 | ||
Corn | 179 | × | 0.44 | = | 0.788 | ||
Pie | 133 | × | 0.54 | = | 0.718 | ||
Biscuit | 75 | × | 1.21 | = | 0.908 | ||
Potato (supper) | 106 | × | 0.36 | = | 0.382 | ||
Cake | 52 | × | 0.90 | = | 0.468 | ||
Apricots | 75 | × | 0.21 | = | 0.158 | ||
Total nitrogen in food | 9.236 | grams. | |||||
Total nitrogen in urine | 8.720 |
Fuel value of the food | 2080 calories. |
Saturday, May 7, 1904.
Breakfast.—Oatmeal 382 grams, milk 100 grams, coffee 185 grams, butter 10 grams, sugar 30 grams.
Dinner.—Bread 93 grams, potato 67 grams, rice pudding 141 grams, milk 200 grams.
Supper.—Bread 67 grams, butter 13 grams, potato salad 122 grams, milk 240 grams, coffee 120 grams.
Fuel value of the food | 1714 calories. |
Sunday, May 8, 1904.
Breakfast.—Oatmeal 386 grams, butter 10 grams, sugar 35 grams, milk 100 grams, coffee 185 grams.
Dinner.—Rice and chicken gravy 178 grams, boiled onions 136 grams, chocolate pudding 141 grams, milk 150 grams.
Supper.—Potato salad 73 grams, bread 28 grams, chocolate cake 104 grams, milk 220 grams.
Food. | Grams. | Per cent Nitrogen. | Total Nitrogen. | ||||
---|---|---|---|---|---|---|---|
Oatmeal | 386 | × | 0.35 | = | 1.351 | grams. | |
Butter | 10 | × | 0.11 | = | 0.011 | ||
Sugar | 35 | × | 0.00 | = | 0.000 | ||
Milk | 100 + 150 + 220 = | 470 | × | 0.55 | = | 2.585 | |
Coffee | 185 | × | 0.11 | = | 0.204 | ||
Rice and chicken gravy | 178 | × | 0.47 | = | 0.837 | ||
Onions | 136 | × | 0.25 | = | 0.340 | ||
Chocolate pudding | 141 | × | 1.03 | = | 1.452 | ||
Potato salad | 73 | × | 0.35 | = | 0.256 | ||
Bread | 28 | × | 1.33 | = | 0.372 | ||
Chocolate cake | 104 | × | 0.95 | = | 0.988 | ||
Total nitrogen in food | 8.396 | grams. | |||||
Total nitrogen in urine | 7.000 |
Fuel value of the food | 1995 calories. |
Monday, May 9, 1904.
Breakfast.—Oatmeal 330 grams, butter 10 grams, sugar 35 grams, milk 100 grams, coffee 185 grams.
Dinner.—Bread 73 grams, fried potato 125 grams, boiled onions 118 grams, macaroni and cheese 128 grams, apple pie 110 grams, milk 200 grams.
Supper.—Bread 82 grams, boiled potato 130 grams, butter 12 grams, chocolate cake 114 grams, milk 245 grams.
Food. | Grams. | Per cent Nitrogen. | Total Nitrogen. | ||||
---|---|---|---|---|---|---|---|
Oatmeal | 330 | × | 0.44 | = | 1.452 | grams. | |
Butter | 12 + 10 = | 22 | × | 0.11 | = | 0.024 | |
Sugar | 35 | × | 0.00 | = | 0.000 | ||
Milk | 100 + 200 + 245 = | 545 | × | 0.58 | = | 3.161 | |
Coffee | 185 | × | 0.099 | = | 0.183 | ||
Bread | 73 + 82 = | 155 | × | 1.33 | = | 2.062 | |
Fried potato | 125 | × | 0.48 | = | 0.600 | ||
Onions | 118 | × | 0.25 | = | 0.295 | ||
Macaroni and cheese | 128 | × | 1.53 | = | 1.958 | ||
Apple pie | 110 | × | 0.55 | = | 0.605 | ||
Boiled potato | 130 | × | 0.30 | = | 0.390 | ||
Chocolate cake | 114 | × | 0.95 | = | 1.083 | ||
Total nitrogen in food | 11.813 | grams. | |||||
Total nitrogen in urine | 7.590 |
Fuel value of the food | 2620 calories. |
Tuesday, May 10, 1904.
Breakfast.—Oatmeal 357 grams, butter 11 grams, sugar 35 grams, milk 100 grams, coffee 185 grams.
Dinner.—Soda biscuit 68 grams, boiled potato 160 grams, butter 20 grams, stewed tomato 103 grams, custard pie 103 grams, milk 200 grams.
Supper.—Soda biscuit 81 grams, butter 14 grams, stewed potato 97 grams, chocolate cake 66 grams, milk 200 grams.
Fuel value of the food | 2190 calories. |
Wednesday, May 11, 1904.
Breakfast.—Oatmeal 394 grams, butter 10 grams, sugar 35 grams, milk 100 grams, coffee 185 grams.
Dinner.—Soup 141 grams, bread 78 grams, butter 14 grams, boiled potato 101 grams, corn 128 grams, rice pudding 116 grams, milk 200 grams.
Supper.—Biscuit 103 grams, butter 11 grams, corn 113 grams, cake 60 grams, milk 205 grams.
Food. | Grams. | Per cent Nitrogen. | Total Nitrogen. | ||||
---|---|---|---|---|---|---|---|
Oatmeal | 394 | × | 0.46 | = | 1.812 | grams. | |
Butter | 10 + 14 + 11 = | 35 | × | 0.11 | = | 0.039 | |
Sugar | 35 | × | 0.00 | = | 0.000 | ||
Milk | 100 + 200 + 205 = | 505 | × | 0.54 | = | 2.727 | |
Coffee | 185 | × | 0.13 | = | 0.241 | ||
Soup | 141 | × | 0.48 | = | 0.677 | ||
Bread | 78 | × | 1.25 | = | 0.975 | ||
Boiled potato | 101 | × | 0.31 | = | 0.313 | ||
Corn | 113 + 128 = | 241 | × | 0.46 | = | 1.109 | |
Rice pudding | 116 | × | 0.63 | = | 0.731 | ||
Biscuit | 103 | × | 1.42 | = | 1.463 | ||
Cake | 60 | × | 0.78 | = | 0.468 | ||
Total nitrogen in food | 10.555 | grams. | |||||
Total nitrogen in urine | 8.280 |
Fuel value of the food | 2183 calories. |
Thursday, May 12, 1904.
Breakfast.—Oatmeal 349 grams, butter 10 grams, sugar 35 grams, milk 100 grams, coffee 185 grams.
Dinner.—Soup 137 grams, fried potato 43 grams, bread 100 grams, macaroni and cheese 122 grams, bread pudding 80 grams, milk 200 grams.
Supper.—Stewed potato 126 grams, bread 122 grams, cake 73 grams, apricots 81 grams, milk 220 grams.
Food. | Grams. | Per cent Nitrogen. | Total Nitrogen. | ||||
---|---|---|---|---|---|---|---|
Oatmeal | 349 | × | 0.41 | = | 1.431 | grams. | |
Butter | 10 | × | 0.11 | = | 0.011 | ||
Sugar | 35 | × | 0.00 | = | 0.000 | ||
Milk | 100 + 200 + 220 = | 520 | × | 0.57 | = | 2.964 | |
Coffee | 185 | × | 0.13 | = | 0.241 | ||
Soup | 137 | × | 0.48 | = | 0.658 | ||
Fried potato | 43 | × | 0.76 | = | 0.327 | ||
Bread | 100 + 122 = | 222 | × | 1.25 | = | 2.775 | |
Macaroni and cheese | 122 | × | 1.94 | = | 2.370 | ||
Bread pudding | 80 | × | 0.82 | = | 0.656 | ||
Stewed potato | 126 | × | 0.43 | = | 0.542 | ||
Cake | 73 | × | 0.78 | = | 0.569 | ||
Apricots | 81 | × | 0.23 | = | 0.186 | ||
Total nitrogen in food | 12.730 | grams. | |||||
Total nitrogen in urine | 9.360 |
Fuel value of the food | 2283 calories. |
NITROGEN BALANCE.—Beers.
Nitrogen Taken in. |
Output. | ||||||
---|---|---|---|---|---|---|---|
Nitrogen in Urine. | Weight of Fæces (dry). | ||||||
May | 6 | 9.236 | grams. | 8.72 | grams. | 17.5 | grams. |
7 | 8.930 | 8.53 | 30.5 | ||||
8 | 8.396 | 7.00 | 26.2 | ||||
9 | 11.813 | 7.59 | 27.1 | ||||
10 | 9.079 | 7.78 | 22.1 | ||||
11 | 10.555 | 8.28 | 26.0 | ||||
12 | 12.730 | 9.36 | 24.5 | ||||
12.5 | |||||||
186.4 | grams contain 5.93% N. |
||||||
70.739 | 57.26 | + | 11.054 | grams nitrogen. | |||
70.739 | grams nitrogen. | 68.314 | grams nitrogen. |
Nitrogen balance for seven days | = | +2.425 | grams. |
Nitrogen balance per day | = | +0.346 | gram. |
Average Intake.
Calories per day | 2152. |
Nitrogen per day | 10.10 grams. |
Here we have, as in the preceding cases, marked physiological economy of non-nitrogenous as well as of nitrogenous food material. Further, taking the body-weight of the subject as 61.5 kilos, and with an average daily excretion of 8.58 grams of metabolized nitrogen, it is evident that under the existing conditions of life and activity there was need for the metabolism of only 0.139 gram of nitrogen per kilo of body-weight. Doubtless, however, still greater economy was possible.
Finally, while it hardly savors of scientific accuracy to quote simple sensations, yet it may be stated that the subject asserts a betterment of his condition, with continuance of mental and physical vigor in such a degree that he has persisted now for more than a year and a half in the maintenance of these dietetic habits which are characterized by this lowered rate of proteid metabolism. The quantity of nitrogen metabolized daily means the breaking down of approximately 50 grams of proteid, and it is very evident that this amount of proteid food, one-half the amount called for by the ordinary diet, is quite sufficient to meet all of the subject’s bodily needs, even with a total fuel value considerably below 2500 calories.
Certain general conclusions seem to be justified by the results reported. A healthy man, whose occupation is such as not to involve excessive muscular work, but whose activity is mainly mental rather than physical, though by no means excluding the latter, can live on a much smaller amount of proteid or albuminous food than is usually considered essential for life, without loss of mental or physical strength and vigor, and with maintenance of body and nitrogen equilibrium. This means that the ordinary professional man who leads an active and even strenuous life, with its burden of care and responsibility, need not clog his system and inhibit his power for work by the ingestion of any such quantities of proteid food as the ordinary dietetic standards call for.[128] There is no real physiological need—that is apparent—for the adoption of such dietetic habits as ordinarily prevail, or as are called for by the dietary standards set by most authorities in this branch of physiology. There is no justifiable ground for the dictum, or the assumption, that the adult man of average body-weight needs daily 118 grams of proteid food for the maintenance of health, strength and vigor, or that there is need for the metabolism of at least 16 grams of nitrogen daily. If such were the case, how could these five subjects, whose experiences have been detailed in the foregoing pages, have maintained their body-weight, established nitrogen equilibrium, pursued their ordinary vocations without loss of strength and vigor, and kept in a perpetual condition of good health, with an average daily metabolism of from 5.4 grams of nitrogen to 8.99 grams of nitrogen for periods ranging from six to eighteen months? Surely, if 16 to 18 grams of nitrogen are a daily requisite for the healthy adult, there should have been some sign of nitrogen starvation during these long periods of low proteid diet, but the sharpest scrutiny failed to find it. On the contrary, there were not wanting signs of improved conditions of the body which could not well be associated with anything but the changes in diet.
Let us briefly consider the main facts. The writer, of 57 kilos body-weight, showed for nearly nine consecutive months an average daily metabolism of 5.7 grams of nitrogen. During the last two months the daily metabolism averaged 5.4 grams of nitrogen. As body-weight and nitrogen equilibrium were both maintained under these conditions, it is certainly fair to assume that the physiological needs of the body were fully met. These figures imply a metabolism, in the first instance, of 0.1 gram of nitrogen per kilo of body-weight, while the lower figure shows a metabolism of 0.094 gram of nitrogen per kilo of body-weight. We may call this latter amount the minimal nitrogen requirement for this particular individual, under which health, strength, and vigor can be fully maintained. This lower nitrogen figure shows[129] that the needs of this particular individual for proteid material are met by the metabolism of 33.75 grams of proteid per day. Hence, one-third the usually accepted standard of proteid is quite sufficient for the wants of this particular person, and this too with a quantity of non-nitrogenous food far below the daily amount called for by ordinary physiological rules. A fuel value of 2000 calories per day was fully adequate to meet the ordinary wants of the body.
Dr. Mendel, with a body-weight of 70 kilos, showed for seven consecutive months an average daily metabolism of 6.53 grams of nitrogen, likewise with maintenance of health, strength, body equilibrium, and nitrogenous equilibrium. This figure implies a nitrogen metabolism of 0.093 gram per kilo of body-weight and shows that the wants of the body—in his case—can be fully met by a metabolism of 40.8 grams of proteid matter daily, and this likewise without increasing the amount of non-nitrogenous food ingested. Indeed, a total fuel value of 2500 calories per day was quite sufficient for all the needs of his body under the existing conditions.
Dr. Underhill, with a body-weight of 65 kilos, showed for six consecutive months a proteid metabolism equal to 7.81 grams of nitrogen per day, while for the last two months the daily average excretion of nitrogen was only 6.68 grams. These figures mean respectively a nitrogen metabolism of 0.120 and 0.102 gram of nitrogen per kilo of body-weight. Here, too, as in the preceding cases, this lowered rate of proteid metabolism was maintained without increasing the total fuel value of the food and with a continuance of health and strength.
Messrs. Dean and Beers, with body-weights of 64 and 61.5 kilos respectively, likewise kept up their health and strength for a long period of time with a nitrogen metabolism averaging 8.99 and 8.58 grams of nitrogen per day, i. e., with a metabolism of 0.140 and 0.139 gram of nitrogen per kilo of body-weight respectively, and this with a total fuel value in their daily food averaging not more than 2500 calories.
With this general concurrence of results, we are certainly warranted in the assertion that the professional man can safely practise a physiological economy in the use of proteid food equal to a saving of one-half to two-thirds the amount called for by existing dietary standards, and this without increasing the amount of non-nitrogenous food consumed. Indeed, the latter class of foods can likewise be diminished in amount without detriment to health or strength, where there is no call for great physical exertion. Lastly, the so-called minimal proteid requirement of the healthy man—which for this group of individuals we may place at the low level of 0.093 to 0.130 gram of nitrogen per kilo of body-weight—represents the real physiological needs of the system for nitrogen, and in so far as our present data show, anything beyond this quantity may be considered as an excess over and above what is required for the actual physiological necessities of the body. Naturally, however, there may be nothing detrimental in a slight excess of proteid beyond the daily needs. That is a subject, however, to be discussed later in connection with other results.
In view of the close agreement in the amount of nitrogen metabolized by these different individuals per kilo of body-weight, emphasis should be laid upon the fact that the results recorded were all obtained with perfect freedom of choice in the matter of diet, without prescription of any kind, so that the close concurrence in the final figures tends to strengthen the value of the data as pointing to a certain minimal requirement easily attainable, and fully adequate for meeting the needs of the body.
The original Detachment from the Hospital Corps of the United States Army detailed to serve in this series of experiments arrived in New Haven September 28, 1903, under the command of Dr. Wallace DeWitt, 1st Lieutenant and assistant Surgeon of the United States Army. The detail was composed of twenty men, of whom fourteen were privates, volunteers for the experiment, the remainder being made up of non-commissioned officers, cook, cook’s helper, etc. The detachment was located in a convenient house on Vanderbilt Square belonging to the Sheffield Scientific School, and there they lived during their six months’ stay in New Haven under military discipline, and subject to the constant surveillance of the commanding officer and the non-commissioned officers.
In selecting the men for the experiment particular attention was paid to securing as great a variety of types as possible, representing different nationalities, temperaments, etc. Naturally, among such a group of enlisted men brought together for the purpose in view many were found unsuited for various reasons, and were quickly exchanged for others better adapted for the successful carrying out of the experiment. Several quickly deserted, apparently not relishing the restrictions under which they were compelled to live. The restriction which constituted the greatest hardship in the eyes of several of the men was the regularity of life insisted upon, and the consequent restraint placed upon their movements in the city when relieved from duty. The following Statement from Dr. DeWitt will explain the causes of removal of the men who dropped out of the experiment during the natural sifting process of the first few weeks and later.
Hospital Corps Detachment U. S. Army,
332 Temple St., New Haven, Conn.,
March 17, 1904.
Professor Russell H. Chittenden,
Director Sheffield Scientific School,
New Haven, Conn.
Sir,—In compliance with your verbal request concerning men of this detachment lost by transfer and desertion and the reasons therefor, I have the honor to inform you that the following men were lost by transfer, at my request, for the reasons set after their respective names:
Private Edward Mcdermott (October 17, 1903). Mentally and morally unsuited.
Private Paul Forkel (October 18, 1903). Physically unsuited.
Private David Acker (October 24, 1903). Physically unsuited by reason of Acute Pulmonary Tuberculosis Bilateral.
Private William C. Witzig (November 17, 1903). Physically unsuited by reason of Cardiac Irritability.
Private Philip S. Myer (December 11, 1903). Physically unsuited by reason of very high grade of Myopia both eyes.
Private first class Charles P. Davis (January 14, 1904). Physically unsuited by reason of Acute Melancholia.
Private Barnard Bates (February 12, 1904). Morally and mentally unsuited by reason of Drunkenness.
In all these men, except Private Davis, the condition for which they were transferred was present when they reported for duty with the detachment.
In the case of Private Davis, his condition of acute melancholia in my opinion was incident to the experiment,—due to the necessary restrictions of liberty and food, assisted by a natural gloomy disposition.
The following men were lost by desertion:
Private first class Samuel R. Curtis (November 3, 1903).
Private first class William Smith (November 5, 1903).
Private Simon Prins (January 23, 1904).
Private Edwin A. Rinard (February 3, 1904).
Of these men Private first class Smith and Private Prins were on duty in the kitchen and were at no time subject to restriction of diet and liberty. Private first class Curtis deserted before the experiment was well under way and can not be attributed to any cause arising out of the investigation. Private Rinard’s desertion was in my opinion due to the restrictions of diet and liberty incident to the experiment. I would say, however, that this man was a worthless character and was discharged “without honor” from the army during a previous enlistment.
Very respectfully,
(Signed) Wallace Dewitt,
1st Lieut. and Asst. Surgeon U. S. Army,
Commdg. Detachment.
As supplementing Dr. DeWitt’s statement it may be mentioned that Rinard reported for the experiment at New Haven on December 11, 1903, and remained here until February 2, 1904. On December 11 he weighed 59.8 kilos, while on February 2, the last day he was here, his body-weight was 60 kilos. Evidently, any restriction of diet he may have suffered had not made any great impression upon his bodily condition.
There were thirteen men of the detachment who really took part in the experiment, and of these all but four were in the original detail. Of these four, two joined in October and two early in November. Of these thirteen, all but two continued to the close of the experiment, April 4, 1904.
The following statement gives the name, age, birthplace, occupation, length of service (U. S. Army), etc. of the thirteen men.
It will be noted that the men range in age from twenty-one years six months to forty-three years, and that representatives of many countries are on the list.
Regarding the duties of the men, i. e., their daily work, the following statement from Dr. DeWitt will give all needed information on this point. The character of the Gymnasium work will be referred to later.
Name. | Age on Oct. 1, 1903 (Years and Months). |
Length of Service on Oct. 1, 1903. (Years and Months). |
Birthplace. | Occupation before Original Enlistment. |
Remarks. |
---|---|---|---|---|---|
Private first class. | |||||
Broyles, Jonah | 24-6 | 3-3 | Campbell Co., Tenn. | Scholar | Joined Nov. 13, 1903. |
Coffman, William E. | 22-1 | 0-2 | Edinsburg, W. Va. | Clerk | Joined Sept. 28, 1903. |
Fritz, Charles J. | 27-8 | 3-0 | Switzerland. | Gasfitter | Joined Oct. 30, 1903. |
Henderson, James D. | 25-1 | 2-0 | Marshall, N. C. | Student | Joined Sept. 28, 1903. |
Loewenthal, Maurice D. | 22-8 | 0-2 | New York, N. Y. | Clerk | Joined Sept. 28, 1903. |
Morris, William | 21-6 | 3-8 | San Juan, P. R. | Scholar | Joined Sept. 28, 1903. |
Oakman, William H. | 43-0 | 1-7 | Blackville, S. C. | Bookkeeper | Joined Sept. 28, 1903. |
Sliney, William F. | 26-7 | 5-0 | Roxbury, Mass. | Painter | Joined Oct. 21, 1903. |
Steltz, John J. B. | 23-1 | 0-3 | Schuylkill, Pa. | Painter | Joined Sept. 28, 1903. |
Zooman, Ben | 25-3 | 1-11 | London, Eng. | Hosp. Orderly | Joined Sept. 28, 1903. |
Private. | |||||
Cohn, Isaac | 21-8 | 0-1 | Jerusalem, Pal. | Porter in Drug store | Joined Nov. 13, 1903. |
Transferred. | |||||
Private first class. | |||||
Davis, Charles P. | 27-0 | 0-2 | Darlington Co. S. C. | Machinist | Joined Sept. 28, 1903; left Jan. 14, 1904. |
Private. | |||||
Bates, Barnard | 26-8 | 1-10 | San Francisco, Cal. | Painter | Joined Sept. 28, 1903; left Feb. 12, 1904. |
Hospital Corps Detachment U. S. Army,
332 Temple Street, New Haven, Conn.,
March 17, 1904.
Professor R. H. Chittenden,
Director Sheffield Scientific School,
New Haven, Conn.
Sir,—In compliance with your verbal request I have the honor to inform you that the duties of this detachment during the tour of duty at this station have been as follows:—
At 6.45 A. M. the men arise and their body-weights are taken immediately, after which they dress and assemble for reveille roll-call.
7.15. Breakfast. After this meal they are all engaged in various duties about the quarters, such as inside and outside police, kitchen police, assisting in measurement of urine and fæces and transportation of the same to the laboratory; cleansing of fæces cans and urine bottles, etc. They are occupied with these various duties until about 9 A. M.
9 A. M. Detachment proceeds to Gymnasium under charge of a non-commissioned officer, and by him reported to the gymnastic instructor.
11 A. M. Detachment returns from Gymnasium.
12 M. Dinner.
1 P. M. Drill, weather permitting, otherwise a walk in charge of a non-commissioned officer, or indoor instruction relative to the duties of a soldier.
2 P. M. Relief from drill; walk, or instruction.
2.30 P. M. Instruction by a non-commissioned officer in their duties as nurses, etc.
3.30 P. M. Relief from instruction.
5 P. M. Supper.
5.30 P. M. Retreat roll-call.
10 P. M. All men in bed.
This routine is the same for every day in the week except Saturday and Sunday. On Saturday drill and instruction in the afternoon are omitted, and on Sundays the men are also free from gymnasium work.
In addition to the duties mentioned above, a special detail of two men is made every morning to assist in the weighing and serving[136] of the food, and from time to time details are sent to the laboratory and reported to Dr. Mendel for such work connected with the investigation as he might assign them.
Very respectfully,
(Signed) Wallace DeWitt,
1st Lieut. and Asst. Surgeon U. S. Army,
Commdg. Det. H. C.
Here we have a group of men, thirteen in number, quite different in type from the preceding group; men accustomed to living a vigorous life under varying conditions, and who naturally had great liking for the pleasures of eating. Further, they were men who had no personal interest whatever in the experiment or in the principles involved. To be sure, they had volunteered for the work, and the objects of the experiment had been fully explained to them. Like good soldiers they no doubt desired to obey orders, and they doubtless preferred to see the experiment a success rather than a failure, but they had not that interest that would lead them to undergo any great personal discomfort. This point should be kept in mind, since it has a distinct bearing upon the possibility of establishing physiological economy of diet in persons who would not willingly incommode themselves or suffer personal inconvenience.
The experiment commenced on October 4, 1903, and for a period of six months every detail bearing upon the nutrition and condition of the men under the gradually changed conditions was carefully observed. Every precaution to preserve the health and good spirits of the men was taken. Pure distilled water was sent to the quarters each morning, magazines and other periodicals were supplied through the courtesy of friends, occasional visits to the theatre were indulged in; in fact all that could be done to counterbalance any possible depressing influence from the partial restraints of the experiment was arranged for.
Regarding the details of the work; the twenty-four hours’ urine was collected by each man, also the fæces for each day, and these were subjected to chemical analysis with a view to[137] following out the various changes in the amount and character of the proteid metabolism going on in the body as measured by the output of total nitrogen, uric acid, and phosphoric acid in the urine, and by the amount of nitrogen in the fæces with reference to the degree of digestion and utilization of the proteid foods ingested.
During the first two weeks the ordinary army rations were given to the men; later a gradual change was made, accompanied by a reduction in the amount of proteid food, with some reduction likewise in the total fuel value of the food. All the food placed before each man was carefully weighed, and at the close of every meal any uneaten food was weighed and the amount subtracted from the initial weights. During the balance periods, when the income and output of nitrogen were carefully compared, the food materials were weighed with greater care and large samples of each article were taken for analysis, to determine the exact content of nitrogen. Every figure for nitrogen shown in the tables was verified by at least a duplicate chemical analysis so as to avoid any possibility of error.
It is not necessary to give here any detailed description of the changes made in the character of the diet, since on pages 288 to 326 may be found the daily dietary from October 2, 1903, to April 4, 1904,—each meal of the day,—showing the amount and character of the food given the men during the six months period. It should be stated, however, that at no time were the men placed on a cereal diet or on a truly vegetable diet. The object in view was simply to study the possibilities of a general physiological economy in diet, with special reference to the minimal proteid requirement of the healthy man. To be sure, in doing this meats, owing to their high content of proteid, were very much reduced in amount and on many days no meat at all was given, but as the dietary is looked through it will be seen that the main change was from a heavy meat diet (rich in proteid) to a lighter diet, comparatively poor in proteid, with an increasing predominance of vegetable and cereal foods. Condiments are also[138] noticeable in the diet, together with the ordinary accessories, coffee and tea. Variety was also considered as a necessary factor, not to be overlooked, as contributing largely to the maintenance of a proper physiological condition.
From a study of the tables which follow, showing the chemical composition of the daily urine, it will be seen that during the first sixteen days, viz., from October 4 until October 20 or 21, when the men were on the ordinary army ration with opportunity to eat an abundance of meat, the daily urine frequently contained 16 to 17 grams of nitrogen, showing a metabolism of over 100 grams of proteid on such days. Sliney, indeed, averaged for four days an output of 18.19 grams of nitrogen, while Coffman, Henderson, and Zooman showed an average daily excretion of about 15 grams of nitrogen each for the sixteen days from October 4.
Any elaborate discussion of the individual results, tabulated in the foregoing tables, seems hardly necessary. To any one interested in the details of the work, a study of the tables themselves will give the necessary information. It may be well, however, to emphasize at once a few of the fundamental points most striking in character which bear upon the main problem. Take, for instance, the case of Oakman, where the data are recorded for every day from October 4, 1903, to April 4, 1904. The degree of proteid metabolism, as indicated by the excretion of nitrogen through the kidneys, is here shown for each day of the six months. Up to November 3, practically for a month, there was not observable any very noticeable change in the rate of proteid metabolism, but commencing with November 4, the nitrogen excretion dropped very rapidly, and as one glances through the daily records for month after month, it is seen that the daily nitrogen output through the kidneys fell to 6 to 8 grams per day, with a daily average excretion of 7.42 grams of nitrogen, as figured from October 21 to April 4.
Further, it will be noted that while the body-weight gradually declined during the first three months, falling from 66.7 kilos down to 62.3 kilos on January 18, from that date on to the close of the experiment the body-weight was practically constant. Here, then, we see, under the use of a prescribed diet quite sufficient in amount to satisfy the cravings of the appetite, a lowering of proteid metabolism equal to that obtained by the individuals of the preceding group. Again, if the body-weight of Oakman is placed at 64 kilos, as representing the average between the initial body-weight and the weight during the last three months, it will be found that the output of metabolized nitrogen per kilo of body-weight amounted to 0.116 gram; not widely different from similar data obtained with men of the preceding group.
Moreover, these results obtained with Oakman are practically duplicated by every other member of this group of soldiers detailed from the United States Army. No exception whatever is to be seen, but every man shows the same lowered[199] proteid metabolism, with practical maintenance of body-weight, with complete satisfying of the appetite, and without loss of health, strength, or vigor, as will be enlarged upon later.
While in the case of Oakman, the nitrogen excreted was determined by an analysis made each day, in the case of the other men of this group the data are given mainly for weekly periods; the results being expressed, however, in the average daily amount for each seven days’ period. By comparing the figures for the daily excretion of nitrogen with the daily dietary, it is easy to trace out the influence of the changes in diet on the extent of nitrogen metabolism.
In considering the changes in the rate of proteid metabolism shown by all the members of this group, it will suffice for present purposes to deal mainly with the average results.
Compare now the average daily output of nitrogen through the urine from November 1 until April 4—a period of five months—of each of these men.
Morris | 7.03 | ⎫ | = 7.80 grams Nitrogen as the grand average. |
Steltz | 7.13 | ⎪ | |
Broyles | 7.26 | ⎪ | |
Loewenthal | 7.38 | ⎪ | |
Oakman | 7.42 | ⎪ | |
Fritz | 7.84 | ⎬ | |
Cohn | 8.05 | ⎪ | |
Coffman | 8.17 | ⎪ | |
Zooman | 8.25 | ⎪ | |
Sliney | 8.39 | ⎪ | |
Henderson | 8.91 | ⎭ | |
Bates | 8.08 | — | Oct. 27-Feb. 11. |
Davis | 8.61 | — | Oct. 26-Jan. 12. |
The figures given show an astonishingly low proteid metabolism for the five months’ period; 7.5 grams of nitrogen in the day’s urine correspond to 46.8 grams of proteid metabolized, while 8.5 grams of nitrogen mean the metabolism of 53.1[200] grams of proteid. In other words, all of these men during a period of five months practically averaged a daily output of nitrogen through the kidneys corresponding to the metabolism of less than one-half the 105 grams of absorbable proteid called for by the so-called standard diets. Further, close scrutiny of the results in the individual tables shows that during many weeks much lower results were obtained than is indicated by the general averages.
Just here emphasis should be laid upon one fact, doubtless of primary importance in any modification of the rate or extent of metabolism in any individual, viz., that in this experiment the daily diet was prescribed, thereby taking from the individual freedom of choice in the selection of food. The writer has no question in his own mind that an intelligent choice of food, coupled with the satisfying of a natural or acquired appetite in moderation, will lead to better results than any system of prescription as to what shall be eaten each day and in what quantity. Still, this is the method necessarily made use of in the present experiment, the writer having prescribed the character and amount of each meal throughout the entire six months’ period, with due regard, of course, to the expressed likes and dislikes of the men.
One feature in the diet compelled by the circumstances of the case also needs to be referred to, namely, the necessity of keeping the men thoroughly satisfied, so that there should be no feeling of hunger, no craving for food. With a person interested in the experiment and desirous of ascertaining the effect of a low nitrogen intake, there would naturally be a willingness to endure, if necessary, for a time some personal discomfort; but with this detail of the United States Army it could not be expected that the men would remain satisfied if they were compelled to undergo the pangs of hunger even for a day or two. Consequently, it was necessary in prescribing the daily diet to see that the quantity of the food was such as to completely satisfy the appetite. This necessitated the use of considerable bulky food of low fuel, and low nitrogen, value. In this way only was it feasible to reduce the[201] nitrogen intake, as well as the fuel value of the food, to the desired level. Practically during the entire six months’ period, with the possible exception of a few days, the men were given sufficient food to completely satisfy their appetites. Throughout the entire period of the experiment, the men all manifested a keen appetite and utilized their food to good advantage, with establishment of the nitrogen metabolism indicated by the foregoing results.
Still confining our attention to the average results regarding nitrogen excretion, we may ask the question, what was the excretion of metabolized nitrogen per kilo of body-weight in the different individuals? This is easily calculated and the data are shown in the following table, in which the figures standing for body-weight are either the data for the month of April, 1904, or else the average between the October and April weights, as in those cases where the body-weight fell off during the experiment.
Body-weight. | Average daily Output of Nitrogen. November-April. |
Metabolized Nitrogen per kilo Body-weight. |
|
---|---|---|---|
kilos | grams | gram | |
Fritz | 74.0 | 7.84 | 0.106 |
Oakman | 64.0 | 7.42 | 0.116 |
Bates | 68.0 | 8.08 | 0.118 |
Morris | 59.0 | 7.03 | 0.119 |
Broyles | 60.0 | 7.26 | 0.120 |
Henderson | 71.0 | 8.91 | 0.125 |
Loewenthal | 59.0 | 7.38 | 0.125 |
Cohn | 63.5 | 8.05 | 0.126 |
Steltz | 53.0 | 7.13 | 0.134 |
Sliney | 60.0 | 8.39 | 0.138 |
Coffman | 58.0 | 8.17 | 0.140 |
Davis | 58.0 | 8.61 | 0.148 |
Zooman | 55.0 | 8.25 | 0.150 |
Scrutiny of these results shows that the daily excretion of metabolized nitrogen ranged in this period of five months from 0.106 gram per kilo of body-weight up to 0.150 gram per kilo of body-weight. Since these men were on essentially the[202] same diet, it is obvious that there were some peculiarities, or personal idiosyncrasies, that tended to modify the exact extent of proteid metabolism, and in some cases at least constituted a more potent factor than body-weight in determining the rate of metabolism. This fact is clearly emphasized in the case of Morris, who, with a body-weight of 59 kilos, showed a proteid metabolism equivalent to only 7.03 grams of nitrogen per day, and Coffman, who, with a body-weight of 58 kilos, showed under the same conditions an average excretion of 8.17 grams of nitrogen per day.
What was the effect of this lowered proteid metabolism upon the bodily condition, especially body-weight? To answer this question the weights of the men are given in the following table, the one column of figures showing the body-weight at the commencement of the experiment, the other column showing the weight at the close of the experiment.
October, 1903. | April, 1904. | ||
---|---|---|---|
kilos | kilos | ||
Steltz | 52.3 | 53.0 | |
Zooman | 54.0 | 55.0 | |
Coffman | 59.1 | 58.0 | |
Morris | 59.2 | 59.0 | |
Broyles | 59.4 | 61.0 | |
Loewenthal | 60.1 | 59.0 | |
Sliney | 61.3 | 60.6 | |
Cohn | 65.0 | 62.6 | |
Oakman | 66.7 | 62.1 | |
Henderson | 71.3 | 71.0 | |
Fritz | 76.0 | 72.6 | |
Bates | 72.7 | 64.3 | February |
Davis | 59.3 | 57.2 | January |
Comparison of these figures shows that six of the men were practically of the same body-weight at the close of the experiment as at the beginning. Of the others, Oakman, Fritz, Cohn, and Bates lost somewhat. Bates, however, was quite stout, and[203] the work in the gymnasium as well as the change of diet tended to reduce his weight. In fact, with the possible exception of Oakman, the slight loss of weight these latter men underwent was a distinct gain to their bodily condition. The most significant feature, however, is to be found on scrutiny of the tables of results for each man, where is seen the body-weight for each day of the six months. Here it will be noticed that, as the experiment progressed, there was, as a rule, a tendency for the body-weight to increase; this was followed by a decline, after which the weight remained practically stationary. This is well illustrated in Oakman’s case. Starting with a body-weight of 66.7 kilos on October 4, he reached 67.6 kilos on November 29, then declining in weight to 62.3 on January 18, after which he remained practically stationary, or varied only within narrow limits.
Finally, it should be said that the low proteid metabolism on which these men were apparently maintaining body-weight was not associated with any increase of non-nitrogenous food. At no time did the fuel value of the daily food reach 3000 calories; in fact, about January 12 the average fuel value of the food was only a little over 2000 calories per day.
Early in January, the body-weight of the men having become practically stationary and the proteid metabolism, as measured by the output of metabolized nitrogen, having been reduced to a low level, an attempt was made to see if the men were truly in a condition of nitrogenous equilibrium. A six-day period was used, during which all the food for each meal was carefully analyzed, the nitrogen in every sample of food being determined in duplicate by the Kjeldahl-Gunning process. The fæces of the period were separated by lampblack, given at appropriate times in gelatin capsules, and all necessary precautions observed to insure an accurate nitrogen balance. The accompanying tables of results give all the necessary data.
The average nitrogen intake per day was 8.23 grams, and the average fuel value of the food per day was 2078 calories. These are the figures for Oakman. With some of the other men there were slight variations from these figures, as shown in the tables—owing to slight variations in diet. Without exception, all the men showed a minus balance, indicating that on this diet the body was losing nitrogen. In other words, the diet as a whole was insufficient for the needs of the body in every case. Whether this was due to lack of sufficient proteid or to an insufficient amount of fat and carbohydrate, i. e., a too low fuel value, cannot be said definitely, but there is every reason to believe that the amount of non-nitrogenous food was insufficient to furnish the requisite fuel value, and consequently body proteid was drawn upon to supply the deficiency. The loss of nitrogen to the body per day varied as a rule from 0.5 to 2.0 grams. In one case only, viz., Broyles, was there a close approach to a balance. In his case there was a minus balance of only 0.12 gram of nitrogen per day.
The average daily output of nitrogen through the urine for this six-days period (Oakman’s case) was 7.52 grams.
Tuesday, January 12, 1904.
Breakfast.—Fried Indian-meal 100 grams, syrup 50 grams, one cup coffee 350 grams, bread 50 grams, butter 15 grams.
Dinner.—Boiled macaroni 250 grams, stewed tomato 250 grams, bread 75 grams, one cup coffee 350 grams.
Supper.—Potato chips 100 grams, fried bacon 25 grams, bread 75 grams, jam 75 grams, one cup tea 350 grams.
Food. | Grams. | Per cent Nitrogen. | Total Nitrogen. | ||||
---|---|---|---|---|---|---|---|
Fried Indian-meal | 100 | × | 0.38 | = | 0.380 | gram. | |
Syrup | 50 | × | 0.051 | = | 0.025 | ||
Coffee (breakfast) | 350 | × | 0.075 | = | 0.262 | ||
Butter | 15 | × | 0.10 | = | 0.015 | ||
Macaroni | 250 | × | 0.53 | = | 1.325 | ||
Stewed tomato | 250 | × | 0.15 | = | 0.375 | ||
Bread | 50 + 75 + 75 = | 200 | × | 1.48 | = | 2.960 | |
Potato chips | 100 | × | 1.09 | = | 1.090 | ||
Bacon | 25 | × | 3.13 | = | 0.780 | ||
Jam | 75 | × | 0.039 | = | 0.029 | ||
Tea | 350 | × | 0.067 | = | 0.234 | ||
Coffee (dinner) | 350 | × | 0.091 | = | 0.318 | ||
Total nitrogen in food | 7.793 | grams. | |||||
Total nitrogen in urine | 6.000 |
Fuel value of the food | 2404 calories. |
Wednesday, January 13, 1904.
Breakfast.—Boiled rice 150 grams, milk 125 grams, sugar 30 grams, butter 10 grams, bread 30 grams, one cup coffee 350 grams.
Dinner.—Hamburg steak with plenty of bread, fat, and onions chopped together 150 grams, boiled potato 200 grams, apple sauce 200 grams, bread 75 grams, one cup coffee 350 grams.
Supper.—Fried rice 100 grams, syrup 50 grams, one cup tea 350 grams, bread 50 grams, butter 15 grams.
Food. | Grams. | Per cent Nitrogen. | Total Nitrogen. | ||||
---|---|---|---|---|---|---|---|
Boiled rice | 150 | × | 0.36 | = | 0.540 | grams. | |
Milk | 125 | × | 0.55 | = | 0.687 | ||
Sugar | 30 | × | 0.00 | = | 0.000 | ||
Butter (breakfast) | 10 | × | 0.10 | = | 0.010 | ||
Bread (breakfast) | 30 | × | 1.66 | = | 0.498 | ||
Coffee (breakfast) | 350 | × | 0.066 | = | 0.231 | ||
Hamburg steak, etc. | 150 | × | 2.80 | = | 4.200 | ||
Potato | 200 | × | 0.29 | = | 0.580 | ||
Apple sauce | 200 | × | 0.067 | = | 0.134 | ||
Bread (dinner) | 75 | × | 1.66 | = | 1.245 | ||
Coffee (dinner) | 350 | × | 0.076 | = | 0.266 | ||
Fried rice | 100 | × | 0.50 | = | 0.500 | ||
Syrup | 50 | × | 0.051 | = | 0.025 | ||
Tea | 350 | × | 0.066 | = | 0.231 | ||
Bread (supper) | 50 | × | 1.66 | = | 0.830 | ||
Butter | 15 | × | 0.10 | = | 0.015 | ||
Total nitrogen in food | 9.992 | grams. | |||||
Total nitrogen in urine | 7.330 |
Fuel value of the food | 2133 calories. |
Thursday, January 14, 1904.
Breakfast.—Boiled hominy 150 grams, milk 125 grams, sugar 30 grams, butter 10 grams, bread 30 grams, one cup coffee 350 grams.
Dinner.—Split pea soup (thick) 200 grams, bread 75 grams, mashed potato 100 grams, pickles 30 grams, one cup coffee 350 grams, pie 120 grams.
Supper.—Suet pudding 150 grams, apple sauce 125 grams, crackers 25 grams, one cup tea 350 grams.
Food. | Grams. | Per cent Nitrogen. | Total Nitrogen. | ||||
---|---|---|---|---|---|---|---|
Boiled hominy | 150 | × | 0.21 | = | 0.315 | gram. | |
Milk | 125 | × | 0.52 | = | 0.650 | ||
Sugar | 30 | × | 0.00 | = | 0.000 | ||
Butter | 10 | × | 0.10 | = | 0.010 | ||
Bread (breakfast) | 30 | × | 1.59 | = | 0.477 | ||
Coffee (breakfast) | 350 | × | 0.096 | = | 0.336 | ||
Split pea soup | 200 | × | 0.69 | = | 1.380 | ||
Bread (dinner) | 75 | × | 1.59 | = | 1.192 | ||
Mashed potato | 100 | × | 0.31 | = | 0.310 | ||
Pickles | 30 | × | 0.054 | = | 0.016 | ||
Coffee (dinner) | 350 | × | 0.075 | = | 0.262 | ||
Pie | 120 | × | 0.50 | = | 0.600 | ||
Suet pudding | 150 | × | 0.78 | = | 1.170 | ||
Apple sauce | 125 | × | 0.058 | = | 0.072 | ||
Crackers | 25 | × | 1.61 | = | 0.402 | ||
Tea | 350 | × | 0.063 | = | 0.220 | ||
Total nitrogen in food | 7.412 | grams. | |||||
Total nitrogen in urine | 8.290 |
Fuel value of the food | 2000 calories. |
Friday, January 15, 1904.
Breakfast.—Wheat griddle cakes 200 grams, syrup 50 grams, one cup coffee 350 grams.
Dinner.—Codfish-balls (4 parts potato, 1 part fish, fried in pork fat) 150 grams, stewed tomato 200 grams, bread 75 grams, one cup coffee 350 grams, apple pie 95 grams.
Supper.—Apple fritters 200 grams, stewed prunes 125 grams, bread 50 grams, butter 15 grams, one cup tea 350 grams.
Food. | Grams. | Per cent Nitrogen. | Total Nitrogen. | ||||
---|---|---|---|---|---|---|---|
Wheat griddle cakes | 200 | × | 0.78 | = | 1.560 | grams. | |
Syrup | 50 | × | 0.051 | = | 0.025 | ||
Coffee (breakfast) | 350 | × | 0.075 | = | 0.262 | ||
Codfish-balls, etc. | 150 | × | 1.77 | = | 2.655 | ||
Stewed tomato | 200 | × | 0.14 | = | 0.280 | ||
Bread (dinner) | 75 | × | 1.59 | = | 1.192 | ||
Coffee (dinner) | 350 | × | 0.075 | = | 0.262 | ||
Apple pie | 95 | × | 0.40 | = | 0.380 | ||
Apple fritters | 200 | × | 0.40 | = | 0.800 | ||
Stewed prunes | 125 | × | 0.15 | = | 0.187 | ||
Bread (supper) | 50 | × | 1.59 | = | 0.795 | ||
Butter | 15 | × | 0.10 | = | 0.015 | ||
Tea | 350 | × | 0.042 | = | 0.147 | ||
Total nitrogen in food | 8.560 | grams. | |||||
Total nitrogen in urine | 7.140 |
Fuel value of the food | 2030 calories. |
Saturday, January 16, 1904.
Breakfast.—Soft oatmeal 150 grams, milk 100 grams, sugar 30 grams, bread 30 grams, butter 10 grams, one cup coffee 350 grams.
Dinner.—Baked macaroni with a little cheese 200 grams, stewed tomato 200 grams, bread 50 grams, tapioca-peach pudding 150 grams, one cup coffee 350 grams.
Supper.—French fried potato 100 grams, fried bacon 20 grams, bread 75 grams, jam 75 grams, one cup tea 350 grams.
Food. | Grams. | Per cent Nitrogen. | Total Nitrogen. | ||||
---|---|---|---|---|---|---|---|
Soft oatmeal | 150 | × | 0.27 | = | 0.405 | grams. | |
Milk | 100 | × | 0.44 | = | 0.440 | ||
Sugar | 30 | × | 0.00 | = | 0.000 | ||
Bread (breakfast) | 30 | × | 1.61 | = | 0.483 | ||
Butter | 10 | × | 0.10 | = | 0.010 | ||
Coffee (breakfast) | 350 | × | 0.075 | = | 0.262 | ||
Baked macaroni, etc. | 200 | × | 0.72 | = | 1.440 | ||
Stewed tomatoes | 200 | × | 0.15 | = | 0.300 | ||
Bread (dinner) | 50 | × | 1.61 | = | 0.805 | ||
Tapioca-peach pudding | 150 | × | 0.087 | = | 0.130 | ||
Coffee (dinner) | 350 | × | 0.093 | = | 0.325 | ||
French fried potato | 100 | × | 0.47 | = | 0.470 | ||
Fried bacon | 20 | × | 3.15 | = | 0.630 | ||
Bread (supper) | 75 | × | 1.61 | = | 1.207 | ||
Jam | 75 | × | 0.039 | = | 0.029 | ||
Tea | 350 | × | 0.099 | = | 0.346 | ||
Total nitrogen in food | 7.282 | grams. | |||||
Total nitrogen in urine | 8.230 |
Fuel value of the food | 1824 calories. |
Sunday, January 17, 1904.
Breakfast.—Boiled Indian-meal 125 grams, milk 125 grams, sugar 30 grams, butter 10 grams, bread 30 grams, one cup coffee 350 grams.
Dinner.—Bean soup (thick) 200 grams, bread 75 grams, mashed potato 100 grams, pickles 25 grams, one cup coffee 350 grams, custard pie 105 grams.
Supper.—Crackers 50 grams, butter 15 grams, stewed prunes 125 grams, sponge cake 100 grams, one cup tea 350 grams.
Food. | Grams. | Per cent Nitrogen. | Total Nitrogen. | ||||
---|---|---|---|---|---|---|---|
Boiled Indian-meal | 125 | × | 0.24 | = | 0.300 | grams. | |
Milk | 125 | × | 0.50 | = | 0.625 | ||
Sugar | 30 | × | 0.00 | = | 0.000 | ||
Butter (breakfast) | 10 | × | 0.10 | = | 0.010 | ||
Bread (breakfast) | 30 | × | 1.61 | = | 0.483 | ||
Coffee (breakfast) | 350 | × | 0.087 | = | 0.304 | ||
Bean soup | 200 | × | 0.86 | = | 1.720 | ||
Bread (dinner) | 75 | × | 1.61 | = | 1.207 | ||
Mashed potato | 100 | × | 0.28 | = | 0.280 | ||
Pickles | 25 | × | 0.054 | = | 0.013 | ||
Coffee (dinner) | 350 | × | 0.081 | = | 0.283 | ||
Custard pie | 105 | × | 0.88 | = | 0.924 | ||
Crackers | 50 | × | 1.61 | = | 0.805 | ||
Butter (supper) | 15 | × | 0.10 | = | 0.015 | ||
Stewed prunes | 125 | × | 0.17 | = | 0.212 | ||
Sponge cake | 100 | × | 1.00 | = | 1.000 | ||
Tea | 350 | × | 0.048 | = | 0.168 | ||
Total nitrogen in food | 8.349 | grams. | |||||
Total nitrogen in urine | 8.140 |
Fuel value of the food | 2081 calories. |
NITROGEN BALANCE.—Oakman.
Nitrogen Taken in. |
Output. | ||||||
---|---|---|---|---|---|---|---|
Nitrogen in Urine. | Weight of Fæces (dry). | ||||||
Jan. | 12 | 7.793 | grams. | 6.00 | grams. | ||
13 | 9.992 | 7.33 | |||||
14 | 7.412 | 8.29 | 5.0 | grams. | |||
15 | 8.560 | 7.14 | 76.0 | ||||
16 | 7.282 | 8.23 | 13.5 | ||||
17 | 8.349 | 8.14 | 9.5 | ||||
104.0 | grams contain 7.39% N. |
||||||
49.388 | 45.13 | + | 7.685 | grams nitrogen. | |||
49.388 | grams nitrogen. | 52.815 | grams nitrogen. |
Nitrogen balance for six days | = | -3.427 | grams. |
Nitrogen balance per day | = | -0.571 | gram. |
Average Intake.
Calories per day | 2078. |
Nitrogen per day | 8.23 grams. |
NITROGEN BALANCE.—Loewenthal.
Nitrogen Taken in. |
Output. | ||||||
---|---|---|---|---|---|---|---|
Nitrogen in Urine. | Weight of Fæces (dry). | ||||||
Jan. | 12 | 7.793 | grams. | 7.33 | grams. | ||
13 | 9.992 | 7.64 | 21 | grams. | |||
14 | 7.388 | 6.21 | 26 | ||||
15 | 8.560 | 8.18 | 52 | ||||
16 | 7.282 | 7.92 | 37 | ||||
17 | 8.349 | 7.26 | 11 | ||||
147 | grams contain 6.97% N. |
||||||
49.364 | 44.54 | + | 10.24 | grams nitrogen. | |||
49.364 | grams nitrogen. | 54.78 | grams nitrogen. |
Nitrogen balance for six days | = | -5.416 | grams. |
Nitrogen balance per day | = | -0.902 | gram. |
Daily diet same as Oakman’s, except that a smaller amount of coffee was taken at breakfast on the 14th. Nitrogen correction made accordingly.
NITROGEN BALANCE.—Steltz.
Nitrogen Taken in. |
Output. | ||||||
---|---|---|---|---|---|---|---|
Nitrogen in Urine. | Weight of Fæces (dry). | ||||||
Jan. | 12 | 7.793 | grams. | 4.61 | grams. | 15.0 | grams. |
13 | 9.463 | 7.90 | 34.0 | ||||
14 | 7.412 | 4.99 | 21.0 | ||||
15 | 8.560 | 9.05 | 31.5 | ||||
16 | 7.282 | 7.56 | 33.0 | ||||
17 | 8.349 | 8.55 | 18.0 | ||||
152.5 | grams contain 6.52% N. |
||||||
48.859 | 42.66 | + | 9.94 | grams nitrogen. | |||
48.859 | grams nitrogen. | 52.60 | grams nitrogen. |
Nitrogen balance for six days | = | -3.741 | grams. |
Nitrogen balance per day | = | -0.623 | gram. |
Daily diet same as Oakman’s, except on January 13, when 8 grams of boiled rice were uneaten at breakfast and 100 grams of fried rice at supper. Correction in nitrogen-content made accordingly.
NITROGEN BALANCE.—Bates.
Nitrogen Taken in. |
Output. | ||||||
---|---|---|---|---|---|---|---|
Nitrogen in Urine. | Weight of Fæces (dry). | ||||||
Jan. | 12 | 7.706 | grams. | 7.46 | grams. | ||
13 | 9.916 | 7.03 | |||||
14 | 7.375 | 7.13 | 36 | grams. | |||
15 | 8.439 | 8.04 | 30 | ||||
16 | 7.226 | 7.66 | 34 | ||||
17 | 8.349 | 7.38 | 34 | ||||
134 | grams contain 7.17% N. |
||||||
49.011 | 44.70 | + | 9.61 | grams nitrogen. | |||
49.011 | grams nitrogen. | 54.31 | grams nitrogen. |
Nitrogen balance for six days | = | -5.299 | grams. |
Nitrogen balance per day | = | -0.883 | gram. |
Daily diet same as Oakman’s, with the following exceptions:
Jan. | 12 | Supper: | 8 | grams | Potato chips, | uneaten. |
13 | Dinner: | 113 | ” | Apple sauce, | ” | |
14 | ” | 50 | ” | Coffee, | ” | |
15 | Supper: | 81 | ” | Prunes, | ” | |
16 | Breakfast: | 75 | ” | Coffee, | ” |
NITROGEN BALANCE.—Coffman.
Nitrogen Taken in. |
Output. | ||||||
---|---|---|---|---|---|---|---|
Nitrogen in Urine. | Weight of Fæces (dry). | ||||||
Jan. | 12 | 7.793 | grams. | 8.82 | grams. | ||
13 | 9.992 | 8.28 | |||||
14 | 7.412 | 8.30 | 57.00 | grams. | |||
15 | 8.560 | 7.91 | 41.25 | ||||
16 | 7.282 | 7.32 | 47.00 | ||||
17 | 8.349 | 7.44 | 21.50 | ||||
166.75 | grams contain 6.66% N |
||||||
49.388 | 48.07 | + | 11.10 | grams nitrogen. | |||
49.388 | grams nitrogen. | 59.17 | grams nitrogen. |
Nitrogen balance for six days | = | -9.782 | grams. |
Nitrogen balance per day | = | -1.630 | grams. |
Daily diet same as Oakman’s.
NITROGEN BALANCE.—Fritz.
Nitrogen Taken in. |
Output. | ||||||
---|---|---|---|---|---|---|---|
Nitrogen in Urine. | Weight of Fæces (dry). | ||||||
Jan. | 12 | 7.793 | grams. | 8.99 | grams. | ||
13 | 9.992 | 6.49 | |||||
14 | 7.412 | 10.26 | 64.0 | grams. | |||
15 | 8.560 | 7.97 | 29.5 | ||||
16 | 7.282 | 5.20 | 62.0 | ||||
17 | 8.186 | 9.40 | 31.0 | ||||
186.5 | grams contain 6.49% N. |
||||||
49.225 | 48.31 | + | 12.10 | grams nitrogen. | |||
49.225 | grams nitrogen. | 60.41 | grams nitrogen. |
Nitrogen balance for six days | = | -11.185 | grams. |
Nitrogen balance per day | = | -1.864 | grams. |
Daily diet same as Oakman’s, except that on the 17th inst. a portion of the prunes was uneaten. Correction made accordingly.
NITROGEN BALANCE.—Henderson.
Nitrogen Taken in. |
Output. | ||||||
---|---|---|---|---|---|---|---|
Nitrogen in Urine. | Weight of Fæces (dry). | ||||||
Jan. | 12 | 7.639 | grams. | 7.68 | grams. | ||
13 | 9.794 | 8.22 | |||||
14 | 7.487 | 8.24 | |||||
15 | 8.560 | 7.76 | 45 | grams. | |||
16 | 7.068 | 7.56 | 26 | ||||
17 | 8.045 | 7.87 | 22 | ||||
93 | grams contain 6.45% N. |
||||||
48.593 | 47.33 | + | 6.00 | grams nitrogen. | |||
48.593 | grams nitrogen. | 53.33 | grams nitrogen. |
Nitrogen balance for six days | = | -4.737 | grams. |
Nitrogen balance per day | = | -0.789 | gram. |
Daily diet same as Oakman’s, except that on several days smaller amounts of coffee and tea were taken. Corrections made accordingly.
NITROGEN BALANCE.—Morris.
Nitrogen Taken in. |
Output. | ||||||
---|---|---|---|---|---|---|---|
Nitrogen in Urine. | Weight of Fæces (dry). | ||||||
Jan. | 12 | 7.255 | grams. | 4.19 | grams. | ||
13 | 9.573 | 7.92 | |||||
14 | 7.325 | 7.91 | 4.75 | grams. | |||
15 | 8.638 | 7.44 | 38.00 | ||||
16 | 7.282 | 7.38 | 71.00 | ||||
17 | 8.349 | 5.28 | 53.00 | ||||
166.75 | grams contain 6.45% N. |
||||||
48.322 | 40.12 | + | 10.75 | grams nitrogen. | |||
48.322 | grams nitrogen. | 50.87 | grams nitrogen. |
Nitrogen balance for six days | = | -2.548 | grams. |
Nitrogen balance per day | = | -0.424 | gram. |
Daily diet same as Oakman’s except that on the first three days smaller amounts of tea and coffee were taken. Corrections made accordingly.
NITROGEN BALANCE.—Zooman.
Nitrogen Taken in. |
Output. | ||||||
---|---|---|---|---|---|---|---|
Nitrogen in Urine. | Weight of Fæces (dry). | ||||||
Jan. | 12 | 7.466 | grams. | 11.31 | grams. | ||
13 | 9.992 | 11.63 | |||||
14 | 7.412 | 9.38 | |||||
15 | 8.560 | 8.44 | 27.5 | grams. | |||
16 | 7.282 | 8.89 | 28.5 | ||||
17 | 8.349 | 8.99 | 13.0 | ||||
69.0 | grams contain 6.46% N. |
||||||
49.061 | 58.64 | + | 4.45 | grams nitrogen. | |||
49.061 | grams nitrogen. | 63.09 | grams nitrogen. |
Nitrogen balance for six days | = | -14.029 | grams. |
Nitrogen balance per day | = | -2.338 | gram. |
Daily diet same as Oakman’s, except that on January 12th 30 grams potato chips were not eaten. Nitrogen intake corrected accordingly.
NITROGEN BALANCE.—Sliney.
Nitrogen Taken in. |
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