carbohydrate /kär″bōhī″drāt/ [L, carbo, coal; Gk, hydor, water] , any of a group of organic compounds, the most important of which are the saccharides, starch, cellulose, and glycogen. Carbohydrates constitute the main source of energy for all body functions, particularly brain functions, and are necessary for the metabolism of other nutrients. They are synthesized by all green plants and in the body are either absorbed immediately or stored in the form of glycogen. Cereals, vegetables, fruits, rice, potatoes, legumes, and flour products are the major sources of carbohydrates. They can also be manufactured in the body from some amino acids and the glycerol component of fats. Symptoms of deficiency include fatigue, depression, breakdown of essential body protein, and electrolyte imbalance. Muscle protein-sparing amounts of food carbohydrates have been estimated to be 50 to 100 grams per day for most people. Excessive consumption of simple carbohydrates is associated with tooth decay and is carefully monitored in persons with diabetes. The dietary reference intake for carbohydrates is 130 grams a day.
