STANDARD BASAL METABOLISM CONSTANTS. 



237 



ILLUSTHATION B. METABOLISM IN CHILDHOOD AND YOUTH AND IN EXTREME OLD AGE. 



In Chapter V we discussed in detail the changes in metabolism 

 which occur with increasing age during the period of adult life. As we 

 indicated there, the limits which mark off the stages of development 

 from the period of maturity and the period of old age from that of 

 extreme old age are very indefinite, or at least are determinable only 

 with difficulty. 



Our equations do not fully represent the metabolism of the develop- 

 mental period. Neither do the observations upon which they are 

 based contain numbers of very old men or women adequately large to 

 justify using them as a standard for determining the influence of special 

 conditions (e.g. the incidence of a specific disease) upon the metabolism 

 of advanced old age. For these very reasons our equations are par- 

 ticularly adapted to determining whether the metabolism of individuals 

 in these extremes of the life-cycle differs from that characteristic of the 

 wide central range of mature life. In applying them to this problem 

 we calculate the metabolism of the individuals of extreme age on the 

 assumption that it is given by inserting the weight, stature, and age 

 of the subjects in the equations based on our adult series. Comparison 

 of the values obtained by actual measurement with that given by the 

 equations then shows whether the metabolism of the age in question 

 differs from that in adult life. 



TABLE 93. Comparison of metabolism of Du Bois boy scouts with the adult masculine normal 



(multiple prediction) standard. 



Consider first the boy scouts studied by Du Bois. 13 The essential 

 details are given in table 93. The computed values are in all cases 

 lower than the observed. The differences range from 115 to 313 

 calories per 24 hours, with an average of 227 calories. Thus boys of 

 12 or 14 years of age have a basal metabolism from 115 to 313 calories 

 per day higher than would be expected if they were adult individuals 

 of the same weight and height. Expressing these results in terms of 

 percentages of the adult standard, as must be done in comparing boys 

 with men, we note that the boys have a metabolism from 9.4 to 28.4 



13 Du Bois, Arch. Intern. Med., 1916, 17, p. 887. 



