GASEOUS METABOLISM DURING REST. 525 



imnce at the low weight level. This involved not only the basal 

 metabolism, but likewise the metabolism necessary for the general 

 activity for the day. From the results of the metabolism experiments 

 we find that this estimated loss in caloric requirement as based upon 

 the caloric intake, using body-weight maintenance as an index, is 

 reasonably substantiated. During the period of diet restriction, we 

 find a lowering of body-weight amounting on the whole to not far from 

 10 to 11 per cent. We also find in periods of complete muscular repose, 

 without extraneous muscular activity, there was a lowering of the heat 

 production per kilogram of body-weight of not far from 20 per cent as 

 computed from the group-chamber tests, making a total effect of 

 caloric saving or a lowering of the total caloric maintenance of not far 

 from 30 or more per cent. The differences found between the basal 

 values in the group chamber (see table 132) and the values obtained 

 with the respiration apparatus vitiate somewhat this generalization, 

 and caution is necessary in these quantitative estimates. 



EFFECT OF EXCESS DIET ON BASAL GASEOUS METABOLISM. 



On several of the uncontrolled Sundays the subjects admittedly ate 

 very large amounts of food.^ Furthermore, as was shown in the dis- 

 cussion of the body-weight measurements (see p. 210), all of the sub- 

 jects increased in weight perceptibly xluring the Christmas vacation 

 and were on a rather free diet. The influence upon the basal metabol- 

 ism of these excess feeding periods may be sharply noted in practi- 

 cally all instances on the return of the men to college in January 

 1918. In a number of instances the gaseous metabolism was also 

 perceptibly increased on the Monday mornings following a Sunday 

 with uncontrolled diet. 



An examination of the values obtained in the morning respiration 

 experiments with the respiratory-valve apparatus shows the effect of 

 the excess food on the metabolism. The oxygen consumption may be 

 used alone for this purpose, as the changes in the respiratory quotient 

 are such as not to affect materially the heat production. Thus, on 

 December 3, after the Thanksgiving recess, Pea had an average 

 oxygen consumption in two periods of 209 c.c. per minute, as com- 

 pared with an oxygen consumption of 192 c.c. on November 22, and 

 of 195 c.c. on December 13. (See table 123, page 508.) With Pec, 

 on October 29, after the uncontrolled Sunday of October 28, the 



^ The occasional Sundays when the diet was more or less uncontrolled we regarded as a neces- 

 sary expedient. Some relaxation from the routine and the usual environment was almost a 

 psychological requirement. The men looked forward with a good deal of pleasure to the occa- 

 sions when they could eat food of their own choice. This made it more possible to keep the men 

 contented and to extend the period of experimental observation. In this connection the intro- 

 spection of Moy is pertinent. On May 21 he said : " It does seem in looking back over the experi- 

 ment that we could have gotten on without the uncontrolled Sundays and the Thanksgiving 

 recess, but these occasions were then greatly appreciated and we would have made an awful kick 

 if they had been curtailed. You simply can not understand the matter. One's point of view is 

 altogether different when he is in the experiment and when he is out of it." 



