METABOLISM 33 



the cell, there is a great preponderance of those of carbo- 

 hydrate and fat, the ' mass influence ' of these asserts 

 itself, the attention of the cell is, as it were, distracted 

 from the protein, and some of the latter safely runs the 

 gauntlet and escapes denitrification. 



Whether or not this represents with any accuracy an 

 approximation to what actually takes place, there can be 

 no doubt of the importance of the influence of the protein- 

 sparers, and the way to ensure the least degree of degrada- 

 tion of protein to the purposes of energy production is to 

 take care that carbohydrates and fats reach the cells 

 along with it. Now, in vegetable foods proteins and 

 carbohydrates are so intimately mixed that this result 

 is achieved without 'difficulty, and hence it is that nitro- 

 genous equilibrium can be more easily attained on a 

 vegetarian diet than on any other. Similarly, if one 

 wishes to maintain life on as low an intake of protein aa 

 possible, care should be taken that the protein food is 

 not mainly consumed at one meal, but that it is spread 

 over the day and mixed with non-protein ingredients. 

 In this way much more of it is likely to escape denitrifica- 

 tion, and be available for purposes of tissue repair. 



It will be evident, then, that part of the protein which 

 is utilized for the production of energy is, so far as its 

 nitrogenous moiety is concerned, wasted, for carbo- 

 hydrate and fat would have served the purpose just as 

 well. This, in point of fact, is the contention of those 

 who say that the ordinary protein-food standard is too 

 high. Indeed, they go further, and say that such pro- 

 tein is not only wasted, but is injurious, in so far as the 

 elimination of the urea and other products of its dis- 



