Written by: Bhavani Swaminathan @aakanksha_dfw

Carbohydrates are considered to be the primary fuel for our body. There are practical reasons for the universal use of carbohydrates in diets. The yield of cereals, the primary source of carbohydrates, is high per unit area. Therefore they are widely available and are an economic source of energy. They are easily packed and have a long shelf-life in dry storage. They are mild flavored and combined well with other foods. Carbohydrate foods are easy to prepare. The members of the simplest form class of carbohydrates have a single unit – monosaccharide, glucose is an example of this class. The disaccharides contain two sugars linked together to form a chain. Cane or beet sugar (sucrose), milk sugar (lactose) and maltose (malt sugar) are members of this class.


Starch is partly hydrolyzed by ptyalin (salivary amylase) in the mouth to dextrose and maltose. Starch and dextrin are further hydrolyzed to maltose by amylase in the small intestine. Maltose, sucrose and lactose are further broken down to glucose, fructose and galactose (simple sugar units) by the enzymes maltase, sucrose and lactase. The glucose formed by the digestion of the starch and sugar is absorbed mainly into the blood through the walls of the intestine and carried to the liver. The glucose thus absorbed helps to maintain the glucose level in blood and the glycogen stores in the muscle and the liver.

Whenever we need energy, the glycogen is broken down to glucose which is oxidized and the energy produced is used by the body. Any excess glycogen is converted to fat.