
126 STORRS AGRICULTURAL EXPERIMENT STATION. 
the respiration calorimeter, but also a large number of experi- 
mental inquiries and observation of dietary usage of people of 
different classes and occupations in different countries, several 
interesting deductions seem warranted at the present time. 
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 
a number of investigators have served a useful purpose, but 
they will doubtless have to be modified as the fundamental 
data become more exact and numerous. 
One principle which thus far has not received adequate rec- 
ognition in dietary standards may perhaps be expressed by 
saying that the standard must vary not only with the condi-. 
tions of activity and environment, but also at the nutritive 
plane at which the body is to be maintained. A man may live 
and work and maintain bodily equilibrium on either a higher 
or lower nitrogen level or energy level. One essential question 
is, What level is most advantageous? ‘The answer to this must 
be sought not simply in metabolism experiments and dietary 
studies, but also in broader observations regarding bodily and 
mental efficiency and general health, strength and welfare. — 
These experiments show the exact quantities of materials and 
energy katabolized in the bodies of young, healthy, active men 
under different conditions of food and fasting, work and rest, 
and it will be interesting to summarize the results as viewed 
from this standpoint. This is done in Table 21. 
The results summarized in the table may be considered with 
relation to the quantities of total food, protein and energy 
katabolized under the different conditions. | 
The quantities of total food in all the experiments except 
the earlier ones with E. O. and those with O. F. T. were rather 
small, the idea being that the body would utilize its food more 
economically with a limited than with an excessive supply. In 
‘the rest experiments the food was nearly or quite sufficient to 
maintain nitrogen and carbon equilibrium during the periods 
spent in the chamber of the calorimeter. 



