198 METABOLISM AND GROWTH FROM BIRTH TO PUBERTY. 



A more careful analysis may be made by comparing the actual heat 

 produced per 24 hours, on an average, for boys weighing 10 kg. and 

 above, with the predicted metabolism calculated from the multiple- 

 prediction formula. These average values are shown in table 33, 

 in which we find that the average predicted metabolism is within 56 

 calories, or a percentage deviation of predicted from actual of 6.3 

 per cent. 



We thus have here a prediction of the metabolism of young boys, 

 based upon the multiple-prediction standard of adults, which shows 

 for the boys weighing 10 kg. or over a remarkable uniformity with 

 that observed from the curve for calories referred to weight. While 

 Harris and Benedict, in putting forth their multiple-prediction methods, 

 specifically stated that its extension to youth under 16 years of age 

 was problematical, it appears that this formula applies to males of all 

 ages of approximately 1 year and over. Considering the rapid changes 

 in weight and stature as compared with the change in age which takes 

 place in this short period from 1 to 13 years, it is an astonishing agree- 

 ment with the masculine adult prediction standards. Below the age 

 of 1 year it is clear that the formula does not hold true, and the curves 

 of either weight referred to metabolism or of surface referred to meta- 

 bolism must be relied upon for prediction. 



The multiple-prediction equations which involve factors for age, 

 weight, and height do not, however, better the situation, since taking 

 all these factors into consideration gives us a prediction with an 

 error identical with that when the values obtained from the curve 

 in figure 26 for weight alone are considered, i. e., 6.3 per cent. It 

 should be remembered in this connection that, during this period of 

 growth, the factors of age, weight, and stature are intimately corre- 

 lated, very much more so than is the case with adults. Adults weigh- 

 ing 70 kg. are much more likely to vary in stature than boys of 30 kg. 

 Similarly, adults weighing 70 kg. may vary in age from early youth 

 to old age, while the variation in age of boys weighing 30 kg. will be 

 very much less. It is thus probable that the body-weights of boys 

 automatically include the variations in age and stature. For practical 

 purposes, therefore, and until the metabolism of children is given 

 biometric analysis, the prediction of the total basal metabolism of 

 boys 10 kg. and above may be made with a reasonable degree of 

 accuracy directly from the curve based upon body-weight. 



PREDICTED HEAT FROM TOTAL CALORIES REFERRED TO 



WEIGHT (GIRLS). 



While the charts that have been discussed thus far give little indi- 

 cation of sexual differentiation in the accuracy or ease of prediction 

 of the metabolism of girls as compared with boys, it has seemed desir- 

 able to consider the boys and girls separately in regard to the prediction 



