408 PHYSIOLOGICAL CHEMISTRY. 



mean about these per cent values: protein 2.2, fat o.i, carbo- 



hydrates 18.4. 100 grams of potatoes would yield then the 

 following : 



Protein ............................ 2.2 gm. 9.0 Cal. 



Fat ................................ o.i 0.9 



Carbohydrate ...................... 18.4 75.4 



A pound of potatoes would furnish, therefore, 386 Cal., and 

 6 to 8 pounds would have to be consumed to furnish energy 

 for ordinarv work. The protein in this would be considerably 

 below the amount which has generally been held necessary, 

 while the fat is scarcely appreciable. The storage of energy 

 on such a diet would be practically impossible. 



On the other hand, a diet of lean meat, round steak for 

 example, would be almost as bad. This averages about 20.9 

 per cent of protein and 10.6 per cent of fat, from which 100 

 grams would furnish 



Protein ........................... 20.9 gm. 85.7 Cal. 



Fat ............................... 10.6 98.6 



184-3 



A pound would furnish 835 Cal. and about 3 to 4 pounds would 

 have to be consumed for support of the body daily. While 

 the fat in this would be proper the protein would amount to 

 275 grams at least, and make the work of excretion extremely 

 difficult. 



As a third case a diet of the small white beans may be con- 

 sidered. We have here protein 22.5, fat 1.8, carbohydrate 

 59.6. In 100 grams, therefore, 



Protein ........................... 22.5 gm. 92.2 Cal. 



Fat ............................... 1.8 16.7 



Carbohydrate ..................... 59.6 244.3 



353-2 



A pound would furnish about 1600 Cal. and 2 pounds would 

 cover the needs of the body practically. The proteins in this 



