A NOKMAL DIET 369 



to be only 70. His factors for the food consumption of growing children 

 were also rather low. Probably these low values are due to the fact 

 that Sundstrom's adult male subjects were all engaged in hard muscular 

 work, rather more severe than the standard "moderate work" used by others 

 whereas the women and children were not so unusually active. If this 

 reasoning is correct, Sundstrom's values should be increased by from 

 10 to 20 per cent. 



Results Reported as Food Consumed Not that Supposed to be Absorbed. 

 Some of the observers whose results are summarized in Table III and IV 

 have reported their findings in terms of "available" calories and "digest- 

 ible" protein, the values being calculated with the aid of factors obtained in 

 metabolism experiments in which the nitrogen content and energy value of 

 the f eces have been regarded as being due to undigested or unabsorbed food. 

 This does not, to the present writer, appear to be justified. The percentage 

 of nitrogen in the feces. is approximately the same no matter what the 

 diet but the amount of feces formed and, consequently, the amount of nitro- 

 gen excreted therein is greater with vegetable material than with animal. 

 However, the relation of fecal nitrogen to food nitrogen after the ingestion 

 of specific foods is not a constant but depends a great deal upon the indi- 

 vidual, upon the method of preparation of the food and the nature of the 

 other constituents of the diet. Thus, Albertoni and Rdssi(a) (1908) 

 found that the addition of meat to the customary vegetarian diet of Italian 

 peasants, although increasing the total nitrogen of the food, diminished not 

 only the relative but also the absolute amount of nitrogen in the feces. 

 On their customary diet containing 75.7 grams protein, three men ex- 

 creted a daily average of 3.21 grams nitrogen in the feces. On diets 

 containing 98.7 grams protein, of which only 21.2 grams was meat pro- 

 tein and the remainder was derived from the customary food, the nitro- 

 gen in the feces was 2.94 grams; and with 111.13 grams protein, of which 

 only 40.8 grams were derived from meat, the fecal nitrogen was 2.16 

 grams. Similar results were obtained with two women, the figures being 

 55.8 grams protein intake without meat with 2.71 grams nitrogen in the 

 feces and 92.6 grams protein, of which 43.3 grams were meat, on the 

 experimental diet, with only 1.533 grams nitrogen in the feces. A similar 

 though much less marked effect of added glucose was observed by Neumann 

 (d) (1919) who found that on a diet of 1000 grams of whole rye bread, his 

 feces contained 2.52 grams nitrogen daily. Upon adding 300 grams 

 glucose to the diet, the fecal nitrogen fell to 2.44 grams and, after in- 

 creasing the glucose intake to 500 grams, to 2.41 grams. 



Again, Hindhede(d) (1914) found that the addition of plums to a 

 bread diet increased the nitrogen of the feces by an amount greater than the 

 total nitrogen of the plums. Hindhede regarded this as evidence of inter- 

 ference with protein absorption but, since there was no such evidence of 

 interference with carbohydrate or fat absorption, it seems possible that the 



