66 FOODS AND NUTKITION 



Again, the fuel value of a food is largely a matter of its 

 fat and carbohydrate content, though the fact that pro- 

 teid has a fuel value makes it a factor. Foods rich in these 

 substances take high rank as energy producers. It is 

 interesting to note that fats have about two and a quarter 

 times the energy producing power of either carbohydrate 

 or proteid. Foods, therefore, which are rich in fats and 

 poor in water have the greatest fuel value. Meats differ 

 greatly in this respect, and while the different cuts and 

 kinds necessarily vary, veal is distinctly the poorest and 

 pork the richest in fat, while mutton and lamb rank with 

 the fatter cuts of beef. Chickens and turkeys rank low 

 in fuel value but high in proteid in spite of their large 

 proportion of refuse. Vegetable foods, though rich in 

 carbohydrates, have less fuel value than fat meats. 



A comparison of vegetable and animal foods from the 

 chart is interesting, and the importance of dry seeds and 

 grains with their small proportion of water and high pro- 

 portion of nutrient is worthy of note. In most of such 

 vegetable foods the proportion of nutrient is not far from 

 87%. Beans and peas are richest in tissue building 

 material, cereals next richest, and fresh vegetables least 

 rich. Vegetable foods, therefore, are good tissue builders, 

 but lack the fuel value of meats owing to the small pro- 

 portion of fat. They are in general less rich in proteid 

 than meats. In this comparison the position of bread as 

 a nearly ideal food is interesting. The flour or vegetable 

 part with its large proportion of proteid and little water 

 has its lack of fat and mineral matter remedied by the 

 addition of lard or butter, milk, and salt, and thus 

 combines the advantages of the cereal with that of the 

 fat meat. 



