INGESTION OF PROTEIN DIETS. 



269 



of this amount of beefsteak. The maximum increment occurred in 

 the second period with all three factors, the percentage maximum for 

 carbon-dioxide production being 27 per cent, for oxygen consumption 

 20 per cent, and for heat production 16 per cent. 



TABLE 200. A. H. M., May 24, 1907. Sitting. (2-hour periods.) 



Beefsteak: 



Amount, 384 grams; nitrogen, 17.63 grams; total energy, 799 cals. 



Fuel value: Total, 644 cals.; from protein, 70 p. ct. ; from fat, 30 p. ct. 

 Basal values (March 6 and 9, 1907): CCh, 51 grams; O2, 46 grams; heat, 164 cals. 



Subject ate beefsteak in lj hours. 



2 Heat eliminated corrected for change in body-weight, but not for change in body-temperature. 

 3 Sample included amount for about j hour without food and for If hours with food preceding 

 this period. 



A. W. W ., May 25, 1907. Although made with a different subject, 

 this is essentially a duplicate of the experiment on May 24, 1907, as 

 the amount of beefsteak ingested (373 grams) is practically the same 

 in both experiments and approximately one-half the amount eaten 

 by A. W. W. in the experiment on April 6, 1907. The nitrogen con- 

 tent of the food was 18.62 grams. The results are given in table 201, 

 and show the same general picture as the data given in table 200, i. e., 

 an increment in the first three periods with a return to the basal metab- 

 olism in the fourth period. A singular fact to be noted is that the 

 maximum effect for all three factors was observed in the third period, 

 although this immediately preceded the return to the basal level. The 

 total increment in carbon-dioxide production was 20 grams, in oxygen 

 consumption 32 grams, and in heat production 45 calories. The total 

 increment in heat production is much less than that found in the com- 

 parison experiment with A. H. M.; the increments for carbon-dioxide 

 production and oxygen consumption also vary considerably in the 

 two experiments. From the results of these experiments it is evident 

 that the ingestion of approximately 375 grams of beefsteak results in 

 an increased metabolism which is essentially completed at the end of 

 6 hours, as the values obtained for the last 2-hour period of both 

 8-hour experiments indicate that the basal level for the metabolism 

 had again been reached. 



