Kirsten Stumpf, age 14, of Duluth, Minn., for her question:
HOW ARE CALORIES FIGURED?
A French chemist by the name of Antoine Lavoisier discovered in 1780 that food and oxygen combined in the body to produce energy. From this came the science of nutrition and man's understanding of how food is turned into fuel for the body. In the early 1900s, full knowledge of vitamins and amino acids and a realization of how they work helped to make us healthier.
Your body must have food, which is used for growth and energy and also for replacing bodily structures that are worn out as you lead your busy life of work and play. Nutrients is the name scientists give this food. The energy in nutrients is measured in units that the scientists call calories.
A calorie is actually a unit to measure heat energy in the metric system of measurement. One calorie is the amount of energy needed to raise the temperature of one gram of water by one degree Celsius.
The word calorie comes from the Latin word calor. it means heat.
The amount of energy needed by people varies, and therefore the need for a certain number of calories each day will also vary from person to person.
Children need more calories each day than adults because they are growing and are also generally much more active. Large people need more than small people and those doing heavy physical work or lots of exercise need more than those who are less active.
Your parents, doctor or school nutritionist can help you determine just how many calories you should be consuming each day. Basically, however, children between 7 and 10 who weigh about 66 pounds should have about 2,400 calories each day. Boys between 11 and 18, weighing between 97 and 134 pounds, should have between 2,800 and 3,000 calories, while girls in the same age group weighing between 97 and 119 pounds should have between 2,100 and 2,400 calories.
A well-balanced diet, with moderate servings of all the needed types of food each day, will generally provide just exactly the right number of calories a person should have.
It's not a bad idea, however, to learn to count calories. Know which food items are rated high and which are low on the scale. Then when it is time to take second helpings, or to select between two snack items, you'll know which choice is best.
One single tablespoon of butter, which is about the amount you may put on your morning toast, has 100 calories. Yet the same number can be obtained in one large apple. And one cup of raw shredded carrots has a calorie count of only 42 while a half-cup of raw cabbage has only 20 calories. One large.raw tomato has about 40 calories while an orange has about 65. Rich cookies and cake, generally, are much higher in calorie count than fruits and vegetables.