96 METABOLISM AND GROWTH FROM BIRTH TO PUBERTY. 



It has been currently believed that the influence of food is con- 

 siderably smaller with children than with adults and that the protein 

 utilized for growth does not participate in the stimulating action 

 formerly termed " specific dynamic action." Frankly, we were misled 

 in some of our earlier observations by this belief, but the evidence 

 here presented certainly gives no indication of a material lessening in 

 the influence of food. Indeed, the general conclusion to be drawn 

 from these data is that the influence of food upon the metabolism of 

 infants is wholly comparable to that noted with adults. This renders 

 all the more potent our contention that basal metabolism measure- 

 ments with young children are not ideal in the commonly accepted 

 definition of the term basal as applied to adults, since they are not 

 made under conditions which preclude the stimulating action of food. 



A rough assumption may be made that the basal metabolism as 

 measured in our series of experiments is, in practically every instance, 

 from 8 to 15 per cent higher than the true basal. This fact must be 

 clearly recognized in the subsequent analysis of the general trend of 

 the metabolism for children of varying ages. In the light of the 

 variations shown in table 23, however, the direct application to our 

 data of this percentage correction is not justifiable. Consequently, 

 until further observations are made upon the quantitative effects of 

 food on the metabolism of children, one can only emphasize the fact 

 that the younger the child is, the greater is the deviation from basal 

 towards a higher measurement of the metabolism. 



It is a matter of regret that the influence of food was not studied 

 with older children, but since it has been made clear that the basal 

 values are too high, especially with the younger children, it is not 

 impossible that these high values may, when corrected, equalize the 

 values for heat production per square meter and bring them more in 

 accordance with those found with adults. On the other hand, it 

 would appear that if a correction were applied for children 6 months 

 and under, it would only further distort the comparison curves for 

 the metabolism. (See discussion of these curves in a subsequent 

 section, page 176.) Final treatment of these curves, i. e., in com- 

 parisons of children ranging in age from birth to puberty, and par- 

 ticularly in comparisons of children with adults, must be subject to 

 the possibility of a correction to obtain the true basal. On the one 

 hand, there will be a distinct objection to establishing a so-called 

 correction on relatively few long experiments; on the other hand, 

 there will be a distinct objection to comparing true basal values 

 with the basal values of youth which are too high as a result of previous 

 food. Except in cases of great weakness and probably disease, no 

 metabolism values for youth may be considered as under basal, the 

 tendency always being for such values to be above rather than below 

 true basal. 



