These results obtained with this body of United States soldiers, living
on a prescribed diet and exposed to the stress and strain of military
discipline with its attendant duties, together with the gymnastic work
and training required each day, confirm in every detail the conclusions
arrived at with the preceding group of professional workers. Once
accustomed to a more sparing proteid diet, less rich in nitrogen, each
one of these subjects had no difficulty in maintaining body-weight on the
simpler and lighter food provided. No great difficulty was experienced
in establishing a condition of nitrogenous equilibrium with this lowered
intake of proteid food, neither was it necessary to increase the amounts
of non-nitrogenous foods (fats and carbohydrates) to accomplish this
end. The bodies of these men were quite able to adjust themselves to
a lowered proteid metabolism, and physiologically speaking, one might
well conjecture whether we have not in this condition a nearer approach
to the normal and ideal state of the body than when the latter is
struggling daily with 118 grams of proteid food, reinforced by fats and
carbohydrates correspondingly increased in amount. However this may be,
the members of the soldier detail were able to live for five consecutive
months with a proteid metabolism corresponding to 7 to 8 grams of
nitrogen per day, with maintenance of body-weight and without discomfort
or loss of bodily vigor.
It was easy in most instances to prove the establishment of nitrogen
equilibrium with a daily intake of 8.5 to 9.5 grams of nitrogen, and with
a total fuel value of the daily food equal to 2500 to 2800 calories. In
other words, a metabolism of less than 50 grams of proteid per day was
quite sufficient for the needs of the body, and a fuel value of 2500
to 2600 calories was ample to meet the requirements of the men under
the then existing conditions of bodily and mental activity. Are we not
justified, therefore, in again asking the question, why should we hold
and teach the doctrine that the healthy adult needs to metabolize
105 grams of proteid food daily? As Voit has well said, the smallest
amount of food that will serve to maintain physiological equilibrium and
keep up health and strength is the ideal diet. The eleven subjects of
this Hospital detachment, who remained throughout the experiment, were
apparently able to maintain physiological equilibrium and preserve their
health and strength under the conditions of diet as described, thereby
demonstrating the possibilities of a physiological economy corresponding
to a saving of full fifty per cent or more in proteid food; a saving
of possibly great physiological import, to say nothing of the possible
economic and sociological importance of the saving. Further, we may add
that the minimal proteid requirement as evidenced by the results of these
experiments is more than fifty per cent lower than the figures quoted by
most physiologists as necessary for the maintenance of life and strength;
and we are certainly justified in the additional statement that if the
figures obtained in these experiments truly represent the _minimal_
proteid requirement of the men under observation, then this minimal
requirement is quite sufficient to meet the physiological needs of the
body for an indefinite period.