Carbohydrates

Carbohydrates

Carbohydrates are one of the main dietary components. This category of foods includes sugars, starches, and fiber.

Alternative Names

Starches; Simple sugars; Sugars; Complex carbohydrates; Diet - carbohydrates; Simple carbohydrates

Function

The primary function of carbohydrates is to provide energy for the body, especially the brain and the nervous system. An enzyme called amylase helps break down carbohydrates into glucose (blood sugar), which is used for energy by the body.

Food Sources

Carbohydrates are classified as simple or complex. The classification depends on the chemical structure of the food, and how quickly the sugar is digested and absorbed. Simple carbohydrates have one (single) or two (double) sugars. Complex carbohydrates have three or more sugars.


Examples of single sugars from foods include:

• Fructose (found in fruits)
• Galactose (found in milk products)

Double sugars include:

• Lactose (found in dairy)
• Maltose (found in certain vegetables and in beer)
• Sucrose (table sugar)

Complex carbohydrates, often referred to as "starchy" foods, include:

• Legumes
• Starchy vegetables
• Whole-grain breads and cereals

Simple carbohydrates are also found in processed and refined sugars such as:

• Candy
• Regular (nondiet) carbonated beverages, such as soda
• Syrups
• Table sugar

Refined sugars provide calories, but lack vitamins, minerals, and fiber. Such simple sugars are often called "empty calories" and can lead to weight gain.

Also, many refined foods, such as white flour, sugar, and white rice, lack B vitamins and other important nutrients unless they are marked "enriched." It is healthiest to get carbohydrates, vitamins, and other nutrients in as natural a form as possible -- for example, from fruit instead of table sugar.



http://www.nlm.nih.gov/medlineplus/ency/article/002469.htm

http://www.netdoctor.co.uk/focus/nutrition/facts/lifestylemanagement/carbohydrates.htm