124 GENERAL SCIENCE 



of water one degree Centigrade. The reason for using a 

 large calorie in measuring the fuel value of foods is to 

 avoid large numbers in recording the fuel value. 



The carbohydrates produce the least amount of heat 

 when oxidized, and so in order to produce the same 

 amount of heat more of that nutrient should be eaten 

 than of the other two. Fats when oxidized produce 

 about two and one-fourth times as much heat as carbo- 

 hydrates. Proteins produce about one and one-half 

 times as much heat as carbohydrates when oxidized. But 

 since protein is a building nutrient, an amount only 

 sufficient for the growth and repair of cells should be 

 eaten, while the other two nutrients should be eaten for 

 the production of heat. The relative amounts of carbo- 

 hydrates and fats that any one person should eat will be 

 determined by the climate in which he lives, by the work 

 done, and by the physical condition of the organs of the 

 body. Carbohydrates and fats taken in the right pro- 

 portion should be eaten in an amount sufficient for the 

 production of just the necessary heat that the body 

 requires. Eating the proper amount of each nutrient 

 will give the bodily organs the least amount of work to 

 do in throwing off poisonous waste products. 



83. Daily Fuel Needs of the Body. It has been 

 stated that the amount of food eaten daily should 

 vary according to climate, the time of the year, the 

 occupation, age, etc. The following table gives the fuel 

 needs of the body at various ages and occupations: 



DAILY CALORIE NEEDS (APPROXIMATELY) 



1. For a child under two years 900 Calories. 



2. For a child from two to five years 1200 



3. For a child from six to nine years 1500 



4. For a child from ten to twelve years 1800 " 



