284 



FOOD INGESTION AND ENERGY TRANSFORMATIONS. 



tails of these experiments, as our main interest lies in the influence 

 of the ingestion of protein upon the heat production as computed from 

 the values for oxygen consumption and carbon-dioxide production. 

 We shall therefore confine our discussion chiefly to the changes in the 

 energy output as the observations continued. The results of the 

 respiration experiments with beefsteak have been summarized on this 

 basis in table 215, which gives the amount of steak eaten, the basal 

 heat production expressed in calories per minute, and the heat pro- 

 duction in calories per minute for successive periods. The data are 

 arranged according to the amount of beefsteak eaten, the largest 

 amount being 362 grams and the smallest 150 grams. The data for 

 the nitrogen excreted, so far as available, are given in table 216. 



TABLE 215. Heat produced (computed) in respiration experiments with beefsteak. 



(Values per minute.) 



1 Time from the moment subject finished eating to the end of the last experimental period; 

 see pp. 151 and 152 for method of obtaining total increase. 



2 Also 15 grams potato chips. Nitrogen in food includes the nitrogen in both beefsteak and 

 potato chips. 



'Additional values were obtained for 7 to 8, 8 to 9, 9 to 10, 10 to 11, 11 to 12 hours as follows: 

 1.39, 1.32, 1.29, 1.21, and 1.31 cals. 



4 Also 15 grams butter and 200 grams beef tea. Nitrogen in food includes nitrogen for all 

 of the food eaten. 



In computing the calories per minute the respiratory quotients as 

 determined were used and not the non-protein respiratory quotients. 

 A calculation of a few of these experiments showed practically no 

 important changes due to a use of the non-protein quotient; 1 accord- 

 ingly we may disregard the calculation and employment of the non- 

 protein respiratory quotient and consider that the calorie output 

 recorded in table 215 represents the heat production. 



1 See p. 203 for comparison made in typical experiments with levulose; similar comparisons made 

 in experiments with beefsteak showed like small differences in the heat production. 



