Carbohydrates are compounds made up of sugars. They come from the starchy part of plant foods. They easily convert to sugar in the body. For this reason, carbohydrates are considered fast fuel.
In general, we can think of carbohydrates as either simple or complex. Simple carbohydrates refer to a single sugar molecule or two sugars linked together. Complex carbohydrates are long chains of sugars linked together.
Simple carbohydrates include the following:
People who live in developed nations generally eat and drink too many simple carbohydrates. A rise in childhood obesity in these countries is linked with this high sugar intake.
Complex carbohydrates are the basis of a healthy balanced diet. Some good sources of complex carbohydrates are:
The food guide pyramid recommends 6 to 11 servings of complex carbohydrates every day. The American Heart Association, called AHA, recommends that 55 to 60 percent of a person's daily calories come from complex carbohydrates. However, AHA warns that a diet too high in carbohydrates can cause changes in blood cholesterol levels. Getting more than 60 percent of daily calories from carbohydrates can raise triglyceride and fat levels. It can also lower the levels of HDL, which is called good cholesterol.
Carbohydrates are found in various foods:
Carbohydrates are found in many foods in the food guide pyramid. They provide over half the calories of a balanced diet. Carbohydrates can be found in the breads, cereals, and grains group at the base of the pyramid. They are also found in the fruit group, the vegetable group, and the milk, yogurt, and cheese groups. In fact, carbohydrates are abundant in all the groups of the food guide pyramid except the meat and meat substitutes group.
The main role of carbohydrates is to provide energy to the body. Carbohydrates are broken down into a form of sugar known as glucose. Glucose is carried to every cell in the body by the blood and can be used right away for energy.
Glucose can be combined into larger sugar units called glycogen, which is a storage form of glucose. A certain amount of glycogen is stored in the liver. It serves as an energy reserve until it's needed by the body. To a lesser degree, glycogen is stored in muscles. It is a key fuel source for the muscles, especially during exercise.
Author:Clare Armstrong, MS, RD
Date Written:
Editor:Crist, Gayle P., MS, BA
Edit Date:10/14/02
Reviewer:Kathleen A. MacNaughton, RN, BSN
Date Reviewed:10/14/02