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: