Ann Marie Rector, age 14, of Erie, Pa., for her question:
IS FAT IN YOUR DIET IMPORTANT?
Fat is one of the most important foods of animals and plants. 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 large amounts of heat. A pure fat has a fuel value of 4,040 calories per pound, while sugar, a typical carbohydrate, has a fuel value of 1,820 calories per pound.
People in cold countries need more fat in their diet than do people in warm countries. Less fat should be eaten in summer, as the body demands less heat then. In winter, more fat should be eaten so that the body can resist cold.
While fat is absolutely essential in a diet, it is important that the amount be kept under control. Ail fat not used for fuel energy, or growth, is stored in the tissues as body fat. And too much body fat can lower the quality of your health.
The bodies of some people do not burn up all the fat that they take in, but store up the excess fat in the body tissues. Such persons generally gain too much weight.
In general, a person can lose this extra weight either by eating less, or by doing more physical exercise, or both. People who wish to lose weight should try to regulate the diet so that the body must draw on its reserve stores of fat.
Each person must follow a diet that is best suited to his own physical condition. A person who is greatly overweight or underweight should consult a doctor for 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 foods.
Fat is digested in the small intestine.
Fatty foods in a diet keep a person from feeling hungry for a longer period of time than do nonfatty foods.
Cooking other foods in fat makes the food tasty, but care must be taken not to overheat the fat covered foods, as this makes them less digestible.
Vitamins A and D are found in most fats. Vitamin A is necessary for growth and vitamin D prevents the disease called rickets. Butter and cream, and the liver oils of cod, halibut and shark contain these vitamins.
Fats are sometimes called glycerides of fatty acids. Some fats are called hard, some soft and some liquid, according to their degree of firmness at ordinary temperatures.
Hard fats include human fat and the fat of beef, mutton and wax. Lard and butter are soft fats. Liquid fats include ail animal and plant oils that stay in a liquid state at ordinary temperatures.
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.