METABOLISM AS AFFECTED BY GROWTH. 141 



to have a metabolism differing widely from the central tendency, it 

 must be remembered that if the chart were extended to the 50 kg. 

 range, the metabolism would be shown to be much nearer the central 

 line, though still above it. On the whole, the values lie reasonably 

 close either side of the line; indeed, so close that the use of this curve 

 to predict the normal metabolism will be subsequently discussed. 

 (See page 188.) 



Attention should be called to the evidence in figure 26 of differences 

 in metabolism, even with children of the same weight. In some 

 instances, i. e., with children weighing 38 or 39 kg., we find a range 

 of from 1,100 to 1,400 calories, or a difference of 27 per cent; and at 

 21 kg. we have one value of 785 calories and another at 985 calories, 

 a difference of 200 calories, or 25 per cent. At about 11 kg. we have a 

 range from 450 to 660 calories, approximately 200 calories, or about 45 

 per cent. Thus w r e see that with certain individuals our extremes 

 may be fairly wide. On the other hand, the general grouping of the 

 points around the central line is suggestive of a clearly denned trend. 



Since the general picture is so similar to that of the chart for calories 

 referred to age, we apparently have here another expression of the 

 fact that as the children increase in age they increase in weight, and 

 that the age chart and the weight chart are more or less inseparable, 

 since weight is inevitably correlated with age and heat production 

 increases both with age and weight. It would be undesirable, how- 

 ever, even to imply that age and weight are of equal or, indeed, of 

 comparable importance in determining basal metabolism. It has 

 been shown with adults that there is a definite influence of age, with, 

 on the average, an actual decrease in the daily heat production with 

 men of about 7.15 calories per year and with women a decrease of 

 2.29 calories per year. 1 Still, this same analysis indicates that the 

 influence of weight far exceeds that of age; hence we must conclude 

 that with children the changes in metabolism noted with different 

 ages are due primarily not to the age element, but to the fact that age 

 changes concurrently with weight. 



TOTAL CALORIES PER 24 HOURS REFERRED TO WEIGHT (GIRLS). 



The values for the girls included in this study are charted in figure 27. 

 The line representing the general trend of metabolism gives a picture 

 of rather rapidly increasing metabolism until the weight of 10 or 12 kg., 

 with a tendency thereafter for the metabolism to increase at a slower 

 rate, which is still present when the weight limit of the chart (39 kg.) 

 is reached. Practically, this chart should have ended at the weight 

 of 31 kg., there being but two values retained beyond this weight. 



The widest deviations of individuals from the general line are, for 

 the most part, well within 100 calories, which, for the higher-weight 



1 Harris and Benedict, Carnegie Inst. Wash. Pub. No. 279, 1919, p. 115. 



