INFLUENCE OF FOOD ON METABOLISM. 



93 



TABLE 23. Heat production of infants after food Continued. 



1 The lowest value, presumably the basal value, is italicized in each series of observations. 



1 The designations for the activity are given the following values: I, very quiet, probably asleep; 

 II, slight movements, few in number; III, some activity, but generally quiet. The 

 method of estimating the activity is described by Benedict and Talbot, Carnegie Inst. 

 Wash. Pub. No. 201, 1914, p. 136. 



The basal metabolism of a child, like that of an adult, is not neces- 

 sarily a fixed factor; hence it is unjustifiable to use a basal value 

 obtained on one day for comparison with the metabolism after food 

 on another day to determine the effect of the food. The question of 

 the selection of a suitable basal value for experiments in such studies 

 has already been exhaustively discussed in a previous publication. 1 

 It was there pointed out that only basal values obtained on the same 

 day were legitimate for comparison with the metabolism after food, 

 and also that the metabolism after one or two days of fast was not a 

 true basal value; also that for ideal comparisons the basal value 

 without food should first be obtained and the metabolism with the 

 superimposed factor of food studied immediately thereafter. 



The most extensive series of observations after food were made with 

 the three children Nos. 123, 131, and 171. Of these, the series with 

 the oldest child No. 171, on March 4-5, 1916, was the longest con- 

 tinued, observations being made for over 11 hours after the food had 



1 Benedict and Carpenter, Carnegie Inst. Wash. Pub. No. 261, 1918, p'. 47. 



