Physiological economy in nutrition, with special reference to the minimal proteid requirement of the healthy man / an experimental study

by R. H. Chittenden

For the rich, as well as for the poor, there is need for careful consideration of this question of intemperance in the daily dietary. Were this the proper place, it would be easy to adduce figures showing the great waste which the consumption of food beyond the physiological requirements of the body entails. It needs no great imagination to picture the enormous saving per capita, in dollars and cents, by a reduction of the daily food to a true physiological basis. The saving to the community, to the family, might well amount to enough to constitute the difference between pauperism and affluence. The resources of a community, as well as the resources of the family, are not to be lightly thrown away. We count the cost of this or that necessity, of this or that luxury, with careful consideration of the relative need and expense, but in the matter of living we pay little heed except it may be to exclude certain dietetic luxuries which seem beyond our purse. We are prone to fancy that health and strength are fostered by great liberality in the amount and variety of the daily food provided, and we are apt to express great concern if all the family and our guests do not avail themselves to the utmost of the foods so lavishly spread before them. The poorer man emulates his richer neighbors as soon as his circumstances will permit, and resources that could be much more advantageously expended for the good of the family and the home life are practically wasted—to say nothing of possible injury to health—under the mistaken idea that this more generous method of living is the surest road to health and strength.

Further, there is ground for thought in the possible economy of time which an improved condition of health would result in for the working members of the family. If greater economy in diet will diminish the number of sick days in the year, thereby increasing the working power of the wage earner, and if greater strength and efficiency can be acquired at the same time, the economic value of the proposition is at once apparent.

Finally, happiness and contentment, which usually appear in direct proportion to the health and prosperity of the individual, may be counted upon as becoming more conspicuous in the life of the community. So we see suggested various ways in which the application of the principles herein laid down, if consistently adopted and followed, may lead to a betterment of economic and sociological conditions. The writer, however, leaves to others, more familiar with sociological problems, the fuller development of this line of thought.

VI. GENERAL CONCLUSIONS.

When this investigation, the results of which have been detailed in the foregoing pages was first planned, it was intended to be simply a physiological study of the minimal proteid requirement of the healthy man, extended over sufficient time to render the results of scientific and practical value. There were no special theories involved, no special system of dietetics in view, but the object was simply to ascertain experimentally the minimum amount of proteid or albuminous food necessary for the maintenance of health and strength, under ordinary conditions of life. The impression in the mind of the writer was that there was no satisfactory scientific evidence to support the views held by most, if not all, physiologists regarding the needs of the body for food, especially nitrogenous or proteid food, and that the dietary standards universally adopted by scientific men were of very questionable accuracy, being founded mainly upon the customs and habits of mankind rather than upon any systematic study of what the actual necessities of the body are.

The results attained have certainly thrown a great deal of light upon this question of minimal proteid requirement, and the experimental study has been throughout a purely physiological one, but as the work has progressed the writer has been more and more impressed with the importance and significance of the results in their bearing upon the broader problem of general physiological economy in nutrition. There is no question, in view of our results, that people ordinarily consume much more food than there is any real physiological necessity for, and it is more than probable that this excess of food is in the long run detrimental to health, weakening rather than strengthening the body, and defeating the very objects aimed at.

Confining our conclusions to general statements, it may be said that our results, obtained with a great diversity of subjects, justify the conviction that the minimal proteid requirement of the healthy man under ordinary conditions of life is far below the generally accepted dietary standards, and far below the amounts called for by the acquired taste of the generality of mankind. Expressed in different language, the amount of proteid or albuminous food needed daily for the actual physiological wants of the body is not more than one-half that ordinarily consumed by the average man. Body-weight (when once adjusted to the new level), health, strength, mental and physical vigor, and endurance can be maintained with at least one-half of the proteid food ordinarily consumed; a kind of physiological economy which, if once entered upon intelligently, entails no hardship, but brings with it an actual betterment of the physical condition of the body. It holds out the promise of greater physical strength, increased endurance, greater freedom from fatigue, and a condition of well-being that is full of suggestion for the betterment of health.

Physiological economy in nutrition means temperance, and not prohibition. It means full freedom of choice in the selection of food. It is not cereal diet nor vegetarianism, but it is the judicious application of scientific truth to the art of living, in which man is called upon to apply to himself that same care and judgment in the protection of his bodily machinery that he applies to the mechanical products of his skill and creative power.

Food requirements must of necessity vary with changing conditions, but with due recognition of this fundamental principle, all the results so far obtained in this investigation, with a great variety of persons, point to the conclusion that the real demands of the body for proteid food do not exceed fifty per cent of the amount generally consumed. One-half of the 118 grams of proteid food called for daily by the ordinary dietary standards is quite sufficient to meet all the real physiological needs of the body, certainly under ordinary conditions of life; and with most individuals, especially persons not leading an active out-of-door life, even smaller amounts will suffice. Excess means waste, but of far greater importance is the unnecessary strain placed upon the body by this uncalled-for excess of food material, which must be gotten rid of at the expense of energy that might better be conserved for more useful purposes.