GENERAL APPLICATIONS AND COMPARISONS 29 



discussing the comparative digestibility of animal and vegetable pro- 

 tein, says that 95% of the former and 85% of the latter are digested. 

 Benedict/^ in comparing the digestibility of animal proteins and fats, 

 found that 97% of animal protein is digested and 84% of vegetable 

 protein. In a mixed diet he found that 92% of the protein was digested. 

 In regard to fats he found that 95% of animal fat was absorbed and a 

 less amount of vegetable fat. Many other investigators have found that 

 vegetable protein is not used by the body to the same extent as animal 

 protein. ^^ ^* 



In regard to the effect of diet upon activity, Thompson,^^ in his 

 studies on dietetics, says: "Meat in general has a more stimulating 

 effect upon the system and is more strengthening than vegetable food, 

 and it gives rise to the sensations of energy and activity." A person^® 

 who changed from a mixed diet to a vegetable one, in describing the 

 effect says : " I, too, felt chilled and sleepy by day and night, so tired 

 that I could hardly walk." This describes the general appearance of 

 the vegetarian rats very closely. Nitti,^'^ in accounting for the greater 

 efficiency of the Italians in the United States than in Italy, attributes it 

 to the fact that their diet here is richer in protein, containing a greater 

 proportion of meat. 



In regard to the amount of protein required, most of the results 

 again are in close accord. 



Caspari^^ concludes that the minimum amount of protein required 

 varies with different individuals, and may also vary in the same individ- 

 ual within wide limits. This is shown in the dietary study^^ of Sandow, 

 the " Strong Man," who consumed 244 grams of protein each day. 

 This is far above the average. 



Chittenden (7) has demonstrated that man can maintain his nitro- 

 genous equilibrium on a diet containing far less protein than the 

 average diet. He has not, however, carried this far enough to deter- 

 mine what effect such a diet would have on the life of the individual 

 or the race. 



Shutt^° found that in hogs fed on a low protein diet — corn only — 

 the meat was inferior and soft. When additional protein was added 

 in the form of milk, the meat was greatly improved. He also states that 

 hogs fed on too high a protein diet had inferior meat. These results 

 were confirmed by Skinner.^^ He adds that hogs fed on corn meal 

 have " poor appetite, light bone, deficient development in valuable por- 

 tions of the carcasses, and a general state of unthrift, as shown by the 

 hair, skin, and hungry look of the animal." When one-sixth of the 

 amount of normal ration rich in protein was added the hogs had normal 

 growth and were in healthy condition. 



