306 



AN AMERICAN TEXT-BOOK OF PHYSIOLOGY. 



estimates are based upon the percentage composition of the foods and upon 

 experimental data showing the extent of absorption of the food-stuffs in each 

 food. In this table he supposes that the daily diet should contain 110 grams 

 proteid = 17.5 grams of N, and non-proteids sufficient to contain 270 grams 

 of C: 



As Munk points out, this table shows that any single food, if taken in quantities 

 sufficient to supply the nitrogen, would give too much or too little C, and the re- 

 verse; those animal foods which, in certain amounts, supply the nitrogen needed 

 furnish only from one-quarter to two-thirds of the necessary amount of C. To 

 live for a stated period upon a single article of food a diet sometimes recom- 

 mended to reduce obesity means, then, an insufficient quantity of either N 

 or C and a consequent loss of body- weight. Such a method of dieting amounts 

 practically to a partial starvation. In practical dieting we are accustomed to 

 get our supply of proteids, fats, and carbohydrates from both vegetable and 

 animal foods. To illustrate this fact by an actual case, in which the food was 

 carefully analyzed, an experimenter (Krummacher) weighing 67 kilograms 

 records that he kept himself in N equilibrium upon a diet in which the pro- 

 teid was distributed as follows : 



300 grams meat 

 666.3 c.c. milk 

 100 grams rice 

 100 " bread 

 500 c.c. wine 



63.08 grams proteid 

 18.74 " 



7.74 " 

 11.32 " 



1.17 " 

 102.05 " 



9.78 grams N. 

 2.905 " 

 1.2 " " 

 1.755 " 

 0.182 " 



= 15.868 



For a person in health and leading an active normal life, appetite and experi- 

 ence seem to be safe and sufficient guides by which to control the diet; but in 

 conditions of disease, in regulating the diet of children and of collections of 

 individuals, scientific dieting, if one may use the phrase, has accomplished 

 much, and will be of greater service as our knowledge of the physiology of 

 nutrition increases. 



