72 METABOLISM AND GROWTH FROM BIRTH TO PUBERTY. 



or may be due to a deficiency in the growth-promoting factors in the 

 diet. In other words, underweight may be simply a concurrent factor 

 with short stature, or, if the height is up to the average and the child 

 is still noticeably underweight, this condition may be due distinctly 

 to an insufficient caloric intake. This latter is the more probable and 

 more common situation. If we refer again to our data for private- 

 school children, we will recall that at all ages they were measurably 

 heavier for their age than were the other normal series that we have 

 reported, both our own laboratory series and the earlier standard series. 

 As we pointed out, however, their greater weight is in large part due 

 to their greater height. Still, the fact that outdoor environment, 

 better medical attention, and probably better dietetic conditions have 

 produced a larger and better conditioned child than the ordinary, 

 especially in our public schools, is a factor that must not be overlooked. 

 So-called " normal weight" is not normal, but is merely average. 

 We believe that our ideal figures, as represented in our curves for 

 private-school children, more truly represent the normal and that 

 pediatricians should strive for the higher weight for age as exhibited 

 by our private-school children rather than for the average weight for 

 age, although here again we clearly recognize the differences in nation- 

 ality in mixed groups, such as those being studied in any of the public 

 schools, and the probably purer strain of nationality in our private 

 schools. 



BODY-WEIGHT IN RELATION TO HEIGHT AS AN INDEX OF 



STATE OF NUTRITION. 



From the foregoing discussion it is obvious that an index of the state 

 of nutrition based on the relationships of height to age and weight 

 to age is subject to very considerable error, because although a child 

 may be of normally short stature with an accompanying small body- 

 weight, due to racial characteristics, on the basis of age he would be 

 considered to be both underheight and underweight. If the short 

 stature is due to racial characteristics and not to deficiency in the 

 growth-promoting factors in the diet, the child may still be considered 

 normal, indeed may be considered ideal. Before this condition can be 

 established, however, a far greater study of the height-weight ratio 

 of children of normally short parents should be made, and in con- 

 sidering the average mixed population of American schools the element 

 of racial characteristics must not be overlooked. 



Having shown that neither an average height for age nor an average 

 weight for age is best suited for an index of nutritional state, since 

 the height may be accompanied by varying weights and vice versa, 

 it is clear that as an index of the best proportional distribution of 

 flesh to skeleton the relationship between height and weight is most 

 satisfactory. For a child of a given height a definite weight is pro- 



