PREDICTION OF THE BASAL METABOLISM OF YOUTH. 197 

 COMPARISON OF THE PREDICTED METABOLISM OF BOYS AND MEN. 



This discussion thus far has been based upon methods of prediction 

 and, indeed, comparison between youths and adults regarding but 

 one physical factor at a time, i. e., weight or surface. Since with 

 adults it has been shown that weight, stature, and age have each an 

 independent influence on basal metabolism, the comparison of youth 

 with adults will not be complete unless the simultaneous use of these 

 factors is made. 



In an earlier report, 1 the metabolism of groups of boys studied by 

 Magnus-Levy and Falk and by Du Bois was compared to the com- 

 puted metabolism of boys by means of the prediction formula derived 

 from the analysis of 136 men, which took into consideration weight, 

 stature, and age changes. It was found that the values for the actually 

 measured metabolism of these boys was invariably very much higher 

 than those computed by the multiple-prediction formula, which 

 assumed that their metabolism was the same as that of adults of like 

 sex, height, weight, and age. The Du Bois boys, in particular, showed 

 an actual measured metabolism very much greater than that predicted 

 from the formula for men proposed by Harris and Benedict. This 

 was in line with Du Bois's interpretation of his own results on the basis 

 of the heat production per square meter. In view of the calculated 

 results obtained for boys by Harris and Benedict, it seems desirable 

 to compute the metabolism of the boys in our study with the multiple- 

 prediction formula for adults, for while the curves in figures 50 and 51 

 show a perceptibly higher heat production per kilogram of body-weight 

 and per square meter of body-surface for boys than with men, it will 

 be important to note if the resultant effect of the three varying factors, 

 age, weight, and height, as included in the prediction by the planar 

 equations, is at all in conformity with the trend in metabolism noted 

 with adults. We have, therefore, computed the metabolism of all 

 of these boys, using the multiple-prediction formula for men, 2 i. e., 

 heat equals 66.4730 + 13.7516w + 5.0033s - 6.7550a. These val- 

 ues have been recorded in table 32, together with the differences 

 between the predicted and actual, both numerical and percentage. 



Although special emphasis has been laid in the foregoing discussion 

 upon boys with body-weights of 10 kg. and over, those with smaller 

 body-weights are likewise included. With the very young children, 

 it will be seen that by the multiple-prediction method the error is 

 practically +100 per cent. The metabolism as predicted is found to 

 be too high in every instance until the boy No. 138, with an age of 

 10 months and 3| weeks, is studied, when a reversal in sign is found. 

 Subsequently, the predicted metabolism seems to be for the most 

 part not far from that actually measured, showing plus and minus 

 values in about equal numbers. 



1 Harris and Benedict, Carnegie Inst. Wash. Pub. No. 279, 1919, pp. 237 and 238. 



2 Ibid., p. 227. 



