26 



VITALITY AND EFFICIENCY WITH RESTRICTED DIET. 



this indicates an adjustment of the body to the excess nourishment. 

 While the main argument is based upon the fact that the body-weight 

 did not change, Grafe presents in addition a number of respiration 

 experiments made during the period of supposed excess feeding, which 

 he compares to a basal value and thus satisfies himself that during the 

 period of excessive feeding there was a very greatly increased nilchtern 

 metabolism. 



At first sight the experiment seems to be carried out with unusual 

 care and accuracy; furthermore, Grafe gives a very good exposition 

 of the main points under discussion. Unfortunately we find it neces- 

 sary to differ with him on several fundamental points regarding his 

 main conclusion that the animal was greatly overfed. During the 

 period of 21 days of starvation the animal lost 5.15 kg. in body-weight 

 and approximately 4 grams daily of nitrogen. During the second 

 period, when the body-weight was being regained, Grafe's figures show 

 that the animal received 2,243.9 net calories per day, and the nitrogen 

 storage almost exactly compensated the nitrogen loss during the hunger 

 period. The measurements of the metabolism during the hunger 

 period, however, show that the total caloric loss during the 21 days was 

 17,403.5 calories.^ Assuming that the caloric loss was the same, 

 whether or not the animal was inside the respiration chamber, the daily 

 loss would be not far from 829 calories. 



During the second period of 7 days, when presumably excess food 

 was given, it is reasonable to assume that the caloric output could not 

 have been much less than 1,000 calories per day. Unfortunately no 

 metabolism experiments after the ingestion of food were made during 

 this period, but in the later experiments reported by Grafe, in which 

 2,600 or more calories were given per day, the caloric output was 1 ,200 

 calories or over; 1,000 calories is therefore a minimum rather than a 

 maximum estimate. Accordingly, during these 7 days at least 7,000 

 calories would be required. Since the dog was given approximately 

 16,000 total net calories the amount available for replenishment of the 

 lost tissue and fat in the body was about 9,000 calories, or about one- 

 half that actually lost during the 21 days. Hence it is clear that it is 

 illogical to reason that the animal body was in its original condition at 

 the end of the 7-day period of feeding. 



In discussing the metabolism in the 29-day period of greatest excess 

 feeding, Grafe has compared it with the minimum metabolism of the 



1 Computed from table II on p. 18 of Grafe and Graham's paper (loc. cit.) as follows: 



