A NORMAL DIET 367 



former are generally neutralized in periods of a week or longer but the 

 latter may be appreciable, particularly in agricultural communities and 

 in others in which transportation and storage facilities have not been 

 well developed. 



The results of observations upon adults of either sex may be reported 

 directly as so much per person, per kilo or per square meter of body sur- 

 face. With groups including both sexes or adults and children, it is es- 

 sential to have some unit in which to express the results. Omitting the 

 periods of pregnancy and lactation, women have a lower food requirement 

 than men because of smaller body weight, lower basal metabolism per kilo, 

 and, as a rule, less mechanical work performed. Children may eat less 

 than adults but consume more per kilo of body weight. 



Choice of Factor for Calculating Food Consumed "Per Man." 

 From time to time, various methods have been proposed for converting 

 observations made on groups including women or children to a "per man" 

 basis. The table (Table II) on page 368 is a compilation of the more im- 

 portant of these, the food requirement of a man of average weight (70 

 kilos or 154 pounds) engaged in a moderate amount of work being taken 

 as 100. The first six columns are copied from the report of the Eltzbacher 

 commission. This was organized in 1914 to survey the food resources 

 and requirements of the German nation. It included in its membership 

 both Zuntz and Rubner. For the value of the food energy requirement 

 of the German people, they used the average of the results calculated by 

 each of the six series of factors. Most other investigators and reporters 

 have used Atwater*s factors and generally the earlier set. These*are cer- 

 tainly in error in giving too low a value to the food requirements of grow- 

 ing children. In fact, recent investigations (Gephart, Holt and Fales) 

 indicate that all the sets of factors used by the Eltzbacher commission 

 and by others are erroneous and that rapidly growing boys and girls re- 

 quire more food than adults. Holt and Fales have tabulated the energy 

 requirements of children at different ages. They regard that of an adult 

 male as 3265 calories per day. From their figures, the author has calcu- 

 lated the factors found in the last column, which are, for American 

 children, probably more accurate than any others hitherto used. There 

 must, of course, be variations in the value of the factors in different parts 

 of the world and among different races due to the variation in the age of 

 attaining maturity and the rapidity of growth at any given age. 



The factor for women is generally taken as 80 (man = 100) though in 

 compiling the report of the U. S. Commissioner of Labor in 1903 it was 

 set at 90 and Rubner (Eltzbacher commission) considered it to be 100. 

 Two series of Russian observations, cited in Table IV, yield the ratios 81.5 

 and 88. respectively. Slosse and Waxweiler in a series of 6 comparisons 

 obtained values for 73 to 95, average 85. On the other hand, Sundstrom* 

 (1908), in his series of observations on Finnish men and women, found it 



