Carbohydrates

Types of Carbohydrates

Carbohydrates are classified as simple or complex based upon their chemical structure, which affects how quickly the sugar is digested and absorbed.

Simple carbohydrates such as fructose in fruit juice or sucrose in table sugar consist of one sugar molecule or two sugar molecules bonded together. Because they are so small, simple sugars require little digestion and are rapidly absorbed. Although this can be beneficial for a quick burst of energy, food and beverages containing simple carbohydrates are often lacking in nutrients and frequent consumption of these foods can contribute to insulin resistance.

Complex carbohydrates such as the carbohydrate chains in fiber have three or more sugar molecules and must be broken down into simple carbohydrates before the body can absorb and metabolize the energy. Foods high in complex carbohydrates are recommended because they provide sustained energy and are often higher in nutrients and fiber, which provide additional health benefits.

Refined Carbohydrates such as white flour have been milled to remove bran and germ. Although they contain complex carbohydrates, many of the benefits have been removed through processing, and most contain added simple carbohydrates, such as sugar.

Food Sources

Simple Carbohydrates

• Table sugar (sucrose)
• High fructose corn syrup
• Fruit sugar (fructose)*
• Milk sugar (lactose)

*While fruit does contain simple sugar, it is also a rich source of other nutrients and should be included in your diet.

Complex Carbohydrates

• Whole grains such as brown rice, oat, whole wheat, quinoa, whole corn, whole grain pastas, and cereals, bulgur, and bran
• Beans and Legumes
• Starchy vegetables such as potatoes and corn
• Other vegetables also contain complex carbohydrate, just in smaller amounts, when compared to more starchy vegetables

Refined Carbohydrates

• White bread
• Pasta
• Baked goods with white flour
• White rice

Function

Glucose is critical for all body cells and needs to be in constant supply in the blood stream.

Carbohydrates break down into glucose, are absorbed into the bloodstream and then are transported throughout the body. Blood glucose levels rise after a meal and then fall back after the glucose is delivered to the cells.

Once the immediate needs of the body have been met, excess glucose is stored in the liver as glycogen. This serves as an "emergency reserve in case blood glucose levels drop too low, but it can only sustain the body for less than one day." When the body is unable to maintain steady glucose levels, diabetes develops. Maintaining diabetics' glucose levels usually requires various hormones, such as insulin and glucagon.