Foods which contain carbon and hydrogen in a form in which they can be oxidized by the body yield heat and other forms of energy to the body. The fuel value of a food is estimated by the amount of heat it will give when oxidized, and is-measured by a heat unit called a calorie.

A calorie is the amount of heat required to raise 1 pound of water 4° F., or 1 kilogram of water 1° C.

The body will require varying amounts of heat and energy under different conditions.

Man sleeping requires......65 calories per hour

Man sitting at rest requires .... 100 calories per hour Man at light muscular work requires 170 calories per hour

Man at active muscular work requires 290 calories per hour Man at severe muscular work requires 450 calories per hour Man at very severe muscular work requires.........600 calories per hour

(Atwater and Benedict)

Food Requirement As Modified By Age And Sex

A woman requires . . .8 amount of food needed by a man

Boy 14 to 17 years . .8 amount of food needed by a man

Children 10 to 13 years .6 amount of food needed by a man

Children 6 to 9 years .5 amount of food needed by a man

Children 2 to 5 years .4 amount of food needed by a man

Less than 2 years . . .3 amount of food needed by a man

Approximate Food Requirement For One Day (H. C. Sherman)

Man doing light muscular work . . 3000 to 3500 calories

Woman doing light muscular work . 2700 calories

Boy 14 to 17 years...... 2500 to 3000 calories

Girl 14 to 17 years...... 2200 to 2600 calories

Children 10 to 13 years...... 1800 to 2200 calories

Children 6 to 9 years..... 1400 to 2000 calories

Children 2 to 5 years..... 1200 to 1500 calories

Children 1 to 2 years..... 900 to 1200 calories