Jenny Lucas, age 14, of Montgomery, Ala., for her question:
IS FAT IN OUR DIET GOOD OR BAD FOR US?
Fat is one of the most important foods of animals and plants. Without it they would die. Fat is definitely good for us and it has a place in everyone's diet. But care should be used in the amount of fat that is eaten each day.
Fats furnish more than twice as much fuel and energy for the body as the same amount of proteins or carbohydrates. This is because fats contain more carbon and hydrogen. When carbon and hydrogen burn, they give off huge amounts of heat.
People in cold countries need more fat in their diets than do people in warm countries. Less fat should be eaten in summer, as the body demands less heat.
The bodies of some people do not burn up all the fat they take in, but store up the excess fat in the body tissues. Such persons generally gain too much weight with diets that are heavy in fats.
In general, a person can lose weight either by eating less, or by doing more physical exercise, or both. People who wish to lose weight should try to regulate their diets so that their bodies will be forced to draw on their reserve stores of fat.
Each person must follow the diet best suited to his own physical condition. A person who is extremely overweight or underweight should very definitely consult a doctor to obtain diet advice.
Nearly all the fat found in food is digestible. But it takes a long time for digestive juices to work on fat. Thus, fried foods that are covered with fat will be digested more slowly than boiled or baked foods.
Cooking foods in fat may make the food tasty, but care must be taken not to overheat the fat covered foods, as this makes them less digestible.
Fat is digested in the small intestine.
Vitamins A and D are found in most fats. Vitamin A is necessary for growth and Vitamin D prevents the disease called rickets.
A pure fat has a fuel value of 4,040 calories per pound.
Some fats are called hard, some soft and some liquid, according to their degree of firmness at ordinary temperatures. Hard fats include human fat, fat of beef and mutton and wax. Lard and butter are soft fats. Liquid fats include all animal and plant oils that stay in a liquid state at ordinary temperatures.
Hard and soft fats may be liquefied by heat, and liquid fats may be hardened by a chemical process called hydrogenation. This process keeps the liquid fats in a solid state so that it does not spoil.
Mineral oils, such as petroleum, are not considered fats because they do not contain combinations of glycerin and fatty acids.
The body does not absorb mineral oils.