nutrientscarbohydrates

Carbohydrates are one of the macronutrients that provide energy for the body's processes. Chemically, they are organic compounds composed of carbon, hydrogen, and oxygen; they occur in a wide range of foods and vary in structure from simple sugars to complex polysaccharides. In nutrition, carbohydrates are often categorized by digestibility (digestible carbohydrates and dietary fiber) and by chemical composition (sugars, starches, and fiber).

Digestible carbohydrates are broken down into glucose, which is used to fuel cells or stored as glycogen in the liver and muscles. When energy intake exceeds needs, glucose can be converted to fat. Dietary fiber is not digested by human enzymes; it reaches the colon where it undergoes fermentation by gut microbiota to form short-chain fatty acids with potential health benefits. Fiber contributes to stool regularity and gut health, and can influence cholesterol and blood sugar responses.

Sources include fruits, vegetables, grains, legumes, and dairy; refined sugars provide energy with little other nutrients and are often limited. Whole foods rich in complex carbohydrates typically also supply vitamins, minerals, and fiber. Dietary guidelines commonly recommend that carbohydrates supply about 45 to 65 percent of daily calories, with added sugars kept to a minimum. Individual needs vary with activity level, health status, and metabolic conditions; low-carbohydrate diets may be used for weight management but should focus on nutrient-dense foods.