CONCERNING LOW PROTEIN DIETARIES 145 



It may be concluded from the evidence so far adduced that a 

 considerable mass of experimental facts and deductions from 

 accurate observation have been accumulated, which, in their 

 general bearing, militate very strongly against the conclusion 

 that a marked reduction in the protein element of the average 

 diet is either necessary or desirable. We have summarized 

 some of the technical and more general objections that a critical 

 examination of Chittenden's investigations on his three groups 

 of subjects would make apparent. The object of our scrutiny 

 of Chittenden's work and of the different points brought forward 

 has been to determine whether the records demonstrate any 

 evidence of ill- effects due to dietetic changes. Several such 

 demerits have been pointed out, and others suggested. 



When a survey is made of Chittenden's brilliant piece of work, 

 it must be admitted that he has made out a very strong case. 

 He has been the first to show that man can live and do a certain 

 amount of work on an intake of protein much below the ordinary 

 accepted standards without increasing indeed, with a con- 

 siderable diminution of the fuel value of the diet. While 

 accepting this finding, we have shown that there remains a 

 considerable degree of doubt whether his subjects did live during 

 the months of experimentation on the low protein dietaries 

 the urinary nitrogen would indicate. 



As pointed out, serious sources of error may have resulted, in 

 the absence of supervision, from the failure of the different 

 individuals to collect and surrender the full amount of the daily 

 urine and to adhere strictly to the diet prescribed. Even during 

 the periods of balance, when the food partaken of was accurately 

 weighed and its nitrogen content estimated, the fact that this 

 nitrogen was computed from certain factors for the percentage of 

 protein of cooked foods leaves open a considerable loophole of 

 error. The great irregularity displayed by the individuals 

 of his second group in their utilization of the protein while 

 on absolutely identical diets does not tend to inspire con- 

 fidence in the accuracy with which the members of the 

 Hospital Corps collected the faeces ; or, if this view be doing 

 them an injustice, and the figures given are correct, then the 

 varying absorption of protein they indicate can only be explained 

 as an ill-effect of the abnormally low protein dietary seriously 

 injuring the absorptive function of the intestinal epithelium. 



These doubts are strengthened when the figures for the fuel 



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