FATTENING 399 



A sharp difference must be drawn between fattening and 

 putting on flesh. 



There are undoubtedly cases in which a true protein up- 

 building takes place; this is seen, for example, in the period 

 of growth, during pregnancy, in functional hypertrophy of 

 the muscles from exercise, and above all in convalescence 

 after sickness and undernutrition. In correspondence to an 

 increased intake of food, which (in contrast to the normal of 

 40 calories per diem for each kilogram of body weight) may 

 reach as much as 70 calories in the first weeks, the energy 

 exchange, for example, in a convalescent from typhoid fever 

 may be found tremendously exaggerated (30 to 50 per cent.) . 

 The respiratory quotient remains generally in the neigh- 

 borhood of 1, as the energy expenditure is chiefly made good 

 by combustion of carbohydrates, while the fat and protein 

 are not burned but accumulate in the economy. 



The usual fattening, as, for instance, that which is prac- 

 tised in such large measures by animal raisers, is truly a 

 putting on of fat. The production of well-muscled animals 

 with large amount of meat is not possible by forced feeding, 

 but only by selective breeding (a proposition which has 

 suffered scarcely any check from occasional observations 

 which have been made upon nitrogen retention after feed- 

 ing abnormally large amounts of protein). Besides fat, 

 water may also contribute to an important degree to the 

 on-put of weight of fattened individuals. This is observed, 

 for example, in the very marked increase of weight seen at 

 first in forced feeding, followed, however, by a pause; at 

 first in such cases there is a marked accumulation of water 

 in the tissues, which is thereafter gradually, with rise of 

 diuresis, replaced by fat. 



If we ask, further, what type of food may be expected 

 to be followed most quickly by increase of fat, the answer 

 would be that protein seems least suited, as an excess of 

 calories provided in protein form is usually not fixed. 



The carbohydrates are much more favorable; there is 



