Part 1
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.
LIST OF ILLUSTRATIONS
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
ACKNOWLEDGMENTS OF FINANCIAL AID IN MEETING THE EXPENSE OF THE EXPERIMENTS HEREIN DESCRIBED
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.
ACKNOWLEDGMENTS OF AID IN THE CONDUCT OF THE EXPERIMENTS
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 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.
PREFACE
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 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.
CONTENTS
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
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
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
PHYSIOLOGICAL ECONOMY IN NUTRITION
INTRODUCTORY
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 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 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 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.