Chap, v.] NUTRITION. 669 



present define than on the kind of food ; of two bodies living 

 on the same diet, and under the same circumstances, one will 

 become fat while the other will remain lean ; and it is an object 

 of the agriculturalist to develope by breeding and selection a 

 "constitution " which will store up the most fat on the cheap- 

 est diet. In fattening animals, the chief care, when the selec- 

 tion of the kind of animal has been made, is to provide adequate 

 carbohydrate food, which as we have seen is the chief fattener ; 

 and the object of the farmer in rearing stock for the butcher is 

 mainly to convert cheap vegetable carbohydrate into dear ani- 

 mal fat. Further aids in fattening may be found in providing 

 repose for the body of such a kind that, while sufficient energy 

 is expended to secure adequate digestion and absorption of food, 

 all causes leading to an increase of metabolism, by which energy 

 is set free and leaves the body, are avoided as much as possible. 



To avoid fat rather than to increase it is often an object of 

 human care. This may be effected by diminishing fats and 

 carbohydrates, but also, in a very marked manner, by relatively 

 increasing the proteids. Proteid food as we have seen augments 

 the whole metabolism of the body, hurrying on the destruction 

 not only of proteid but of carbon food ; and a tendency to cor- 

 pulency may be counteracted by a diet in which fats and carbo- 

 hydrates are much restricted, and proteids are largely increased. 

 When, as in what is known as the Banting method, the diet is 

 almost exclusively proteid, the nitrogenous overwork entails 

 dangers on organisms which do not possess the power of ridding 

 themselves freely of the large amount of nitrogenous waste 

 which such a diet produces. A less severe method in which 

 the fats and carbohydrates are diminished only, not entirely 

 done away with, and the proteids only moderately increased, 

 is less open to objection ; and such a diet, assisted by other 

 hygienic conditions, has proved successful. 



An increase of daily food, largely proteid in nature, given 

 under circumstances, such as a large amount of passive exercise 

 and skin stimulation, known as ' massage,' which will not only 

 favour digestion but also promote metabolism in general, may 

 be given, with favourable results. In this way, an enormous 

 metabolism may be excited, and yet so carried on that the body 

 gains both in flesh and in fat. Thus, in one case, the patient 

 with an initial weight of 45 kilos, and a daily nitrogenous 

 metabolism, calculated as 28 grm. proteid, reached in the course 

 of about 50 days a weight of 60 kilos, the daily nitrogenous 

 metabolism being raised on one occasion to 182 grm. proteid, 

 with an average on the whole period of 150 grm. During the 

 treatment no less than 8420 grm. of proteid were taken as 

 food. 



§ 447. With regard to labour, since as we have seen the 

 energy expended as work done is not taken out of and away 



