The principle source of energy for the body, carbohydrates are made up of carbon, hydrogen and oxygen molecules that are digested in the small intestines, metabolized, processed in the liver and converted to blood sugar or glucose.
These sugars supply energy for strengthening organs, regulating the blood and maintaining the brain and nervous system. Vehicles for carbohydrates include fruits (with simple sugars) and grains (with complex sugars). Simple sugars include oranges and berries while complex sugars include potatoes, breads and pastas.
Grains and other carbs make up more than 50% of most people's dietary intake, according to nutritionists who maintain, as well, that carb consumption does not only aid in brain function and intestinal health, but helps control weight if managed according to the USDA food pyramid. It is the reciprocal play between glucose and insulin that thusly regulates weight gain.