Carbohydrates, is one of the major nutrients. It is the energy provider for voluntary and non–voluntary functions of the body. Carbohydrates present in cereals, pulses, roots and tubers are usually in form of sugars and starches. Sugar is 100% carbohydrate. As it is present in a simpler form, it gets digested and absorbed faster. Vegetables, fruits, and the outer cover of cereals & pulses all contain carbohydrates. These are fibrous and not digested or absorbed in human intestine, but eliminated as waste products.

As they are not available to the human body for use they are also known as unavailable carbohydrates. However, they help maintain the muscle tone of the gastro–intestinal tract and ensure normal peristaltic movement. This helps in avoiding constipation.

Soluble unavailable carbohydrates like pectin, lignin help in maintaining serum cholesterol, triglycerides and glucose levels, thereby playing an important role in the diet of patients suffering from arteriosclerosis, hypertension, CHD and diabetes. Unavailable carbohydrates provide bulk without adding to calories and are useful in the weight reducing regime. About 60 to 70% of total energy should be sourced from carbohydrates. A typical Indian diet supplies 70 to 75% calories from carbohydrates. While in western countries carbohydrates provide only 40 to 50 % calories.

While inadequate consumption of carbohydrate may lead to under–nutrition, too much carbohydrate may lead to obesity. As part of the intake is stored in the form of glycogen in liver and muscle and the remaining in the form of fat in adipose tissues. A minimum of a 100 gm. of carbohydrate is needed in the diet to ensure efficient oxidation of fats.