Your body needs the right kind of calories to stay healthy

"How many calories are in pop?" asked Ariel Walker of Gurnee. Walker, 11, is a fifth-grader at O'Plaine School in Gurnee.

A calorie is a unit of food energy. Bodies need a combination of vitamins, minerals, fats, fiber, carbohydrates, water, proteins and other nutrients from food or drinks so they can be healthy and strong.

"Your organs need calories to work similar to how a car needs gas," said Dr. Rebecca Unger, pediatrician with Northwestern Children's Practice in Chicago and Children's Memorial Hospital. Calories are in almost everything you eat and drink. When you walk, run and even sleep, your body burns calories; that is, the fuel from calories makes your body work. That's why it is so important to watch what you eat.

Calories are in the news because of a concern that many people are overweight. If you eat and drink exactly the right amount of calories for your body size and activity level, you won't gain weight. "It's a balance between calories in and calories out," Dr. Unger said. If you ingest too many calories you will gain too much weight and become sick. "Body mass index is used to see if a child is growing in a healthy way. It's the relationship between weight and height," Dr. Unger said.

The right mix of calories keeps your body fit and also keeps you body healthy. Many diseases are related to eating the wrong mix of calories, like heart disease and anemia. Too few calories can lead to starvation.

An average portion of stewed chicken, without skin, is 190 calories. The nutrients in the chicken are helpful to your body systems. An 8-ounce glass of a soft drink is about 100 calories and has no nutritional value. Some experts believe the sugar in soda pop and other sweetened drinks could promote overeating.

"Juice can also be a poor choice," Dr. Unger said, especially if it contains high fructose corn sugar. "Drink these things in moderation, like a special treat," Dr. Unger said. "But you should drink healthy things like milk for the vitamin D and calcium it provides. Vitamin D is not present in all dairy products. Soda pop shouldn't take the place of healthy foods."

Before you eat, take a look a food's nutritional labels. Labels provide information about calories, nutrition and recommended quantities to eat or drink.