216 PEARL— STAPLE COMMODITIES AND 



that any inference from dietary studies, as they have been carried 

 on, to the whole population rests on an exceedingly dubious founda- 

 tion. It will therefore be of great interest to compare the results 

 of the present careful investigation of the population as a whole 

 with the results of previous dietary studies. 



In reducing consumption data to a per capita basis it would ob- 

 viously be foolish to take the actual total population as a base, for 

 the reason that the amount of food consumed changes with the age 

 of the individual, particularly in early life. On account of this fact 

 the usual practice in computations of this kind is to reduce, not to a 

 per capita basis, but to an adult man basis. In doing this a frac= 

 tional factor is used to multiply the number of individuals of certain 

 lower ages, the magnitude of the factor being proportional to the 

 relation which the nutritional intake of the individual at the younger 

 age bears to that of an average adult man. 



In the present study the following age-intake factors have been 

 used : 



Age in Years. Man Value Factor. 



0-5 0.50 



6-13 0.77 



14-18, male i .00 



14-18, female 0.83 



19 on, male i.oo 



19 on, female 0.83 



The man factor values here used have been adopted after care- 

 ful study of the subject. They differ in detail somewhat from those 

 adopted by English physiologists in similar calculations, but in the 

 net end result come to much the same thing. 



Applying these factors to the total population of the United 

 States, and assuming that the age distribution of the population is _ 

 the same in each of the years studied, we get the population in terms 

 of adult men as set forth in Table XIV. for the midyear point of 

 each of the years included in this study. The population equiva- 

 lents in Table XIV. are used for the base for the per capita per diem 

 calculations which follow. 



Before entering on the detailed discussion of per capita con- 

 sumption figures it is well to recall a fact which is liable to escape 

 attention, unless special attention is called to it. This is the fact 



