THE PROTEIN REQUIREMENTS OF MANKIND 121 



could live on considerably less protein than the individual of 

 average physique, thus lowering the average amount of nitrogen 

 metabolized for the whole series. However, leaving that aside, 

 and taking notice only of the amount of nitrogen metabolized 

 per kilo of body weight, we find for the 108 students the 

 following facts as contrasted with Chittenden's results : 



That is, on an average, over the whole series there is a deficiency 

 of 0-011 gramme of nitrogen per kilo of body weight compared 

 with Voit's standard dietary. Considering that this result is 

 obtained from a single day's collection of the urine, it must be 

 acknowledged to approximate very closely to the ordinary 

 accepted standards. 



For these different reasons, it cannot be admitted that Chitten- 

 den has proved that these men, picked at random from a group 

 of several thousands, habitually live on a much smaller amount 

 of protein food than is called for by the commonly accepted 

 standards. By working out the difference as contrasted with 

 Voit's standard on a basis of nitrogen metabolized per kilo of body 

 weight, 0-217 gramme is just over 95 per cent, of the metabolism 

 permitted by Voit's dietary. This is a comparatively small 

 difference, even were it based on results arrived at by strictly 

 accurate methods, on which to attack the findings of physiologists 

 all over the world, which findings show with almost universal 

 unanimity that, where a free choice can be afforded, mankind 

 consumes sufficient food materials to provide at least 100 grammes 

 of protein on the average in his daily fare. 



Incidentally, it shows that the subjects selected for observation, 

 although they were considerably below the average weight of the 

 normal American, only 66 kilos, the average American weighing 

 70 kilos, instinctively selected sufficient protein to maintain the 

 level of their nitrogenous metabolism at very nearly the average 

 height. They were not, therefore, " living at a dangerously low 

 level of nitrogen intake, nor unconsciously undermining their 

 health, and gradually destroying their vitality." 



