rs ste 2 fel 
ge, OP ae * 
108 STORRS AGRICULTURAL EXPERIMENT STATION. 
gains and losses of the nitrogen and carbon.* Accordingly, 
the figures show the average daily amounts of available protein 
and energy supplied by the food and the amounts actually used 
by the body when the subject had a minimum amount of exer- 
cise and when he was engaged in decidedly active muscular 
work. 
The materials actually oxidized in the body are the available 
nutrients of the food minus the protein or fat gained or plus the 
protein or fat lost by the body. The data in the table show 
very clearly the demands of the body under the different con- 
ditions, and the increase in the demand which accompanied the 
performance of muscular work. In the rest experiments, the 
amounts of nitrogen in the available food and in the materials 
actually oxidized were larger with E. O. than with the other 
subjects. "he amounts of carbon and energy in the available 
food were also larger with E. O., but there was comparatively 
little difference in the amounts actually metabolized. In the 
work experiments the amounts of nitrogen in the available 
food and in the material oxidized were not greatly different, 
for any of the subjects, from those in the rest experiments. 
The amounts of carbon and energy, however, were somewhat 
larger, the greatest increase in the amounts metabolized being 
in the case of A. W. 5S. 7 
These experiments simply show the quantities of material 
and energy metabolized by a small number of men under 
specific conditions of work and rest. Their bearing upon the 
general subject of dietary standards can: be more advanta- 
geously discussed when it is possible to take into account not 
only these and other experiments with men in the respiration 
calorimeter, but also a large number of experimental inquiries 
and observations of dietary usage of people of different classes 
and occupations in different countries. 
There is no doubt that in many cases the body can be main- 
tained in nitrogen and carbon equilibrium with much smaller 
quantities of nitrogen and energy than those actually used by 
any of the men in these experiments. It is equally certain 
that in other cases the requirements are much larger. The 
tentative standards for daily diet which have been proposed by 

_* By the method previously described, U. S. Dept. Agr., Office of Experiment Sta- 
tions, Bul. 69, pp. 44, 45. 
