626 



METABOLISM, NUTRITION AND DIETETICS 



necessary 250 grammes carbon. Of course a diet consisting, week 

 in week out, entirely of potatoes or rice, would represent an extreme 

 case, and no doubt the total nitrogen ingested would be considerably 

 below the usual proportion. A certain amount of the necessary 

 nitrogen is obtained even by the poorest populations, in the form 

 of fish, milk, eggs, or bacon. A man attempting to live on flesh alone 

 would be well fed as regards nitrogen with 500 grammes of meat, 

 but nearly four times as much would be required to yield 250 

 grammes of carbon. Oatmeal and wheat-flour contain nitrogen and 

 carbon in nearly the right proportions (i N: 15 C), oatmeal being 

 rather the better of the two in this respect ; and the best-fed labour- 

 ing populations of Europe still live largely on wheaten bread, while, 

 one hundred years ago, the Scotch peasant still cultivated the soil, 

 as the Scotch Reviewer the Muses, ' on a little oatmeal. ' But 

 although bread may, and does, as a rule, form the great staple of 

 diet, it is not of itself sufficient. 



It is necessary to recognize that habit has much to do with the 

 quantity as well as the quality of the food used by an individual 

 or a community. Some concession may be made to custom in 

 what is after all, not a purely physiological question, and in this 

 country it is probable that 20 grammes of nitrogen and 300 grammes 

 of carbon, while a liberal is not an excessive allowance, although 

 it is certain that a man can maintain a normal body-weight and 

 perform a normal amount of work on considerably less, in some 

 cases even with advantage to his health. 



We may take 500 grammes of bread and 250 grammes of lean 

 meat as a fair quantity for a man fit for hard work. Adding 



* A cheese manufactured from whole milk, curdled before the cream has 

 had time to rise, and therefore rich in fat. 



