Carbohydrates

About Carbohydrates

Carbohydrates are a macronutrient that provides 4 calories per gram and the main fuel for the brain and for muscles during intense exercise. Dietary guidelines set an acceptable range for the share of energy from carbohydrate. They are classified as simple sugars, including the monosaccharides glucose, fructose and galactose and the disaccharides sucrose, lactose and maltose, and complex carbohydrates, including the starches amylose and amylopectin and dietary fiber. The body stores carbohydrate as glycogen in the liver and muscles. The glycemic index ranks foods by how much they raise blood glucose, and the glycemic load also accounts for the amount eaten. The World Health Organization and many national guidelines advise limiting free and added sugars. High sugar intake is linked to obesity, type 2 diabetes, cardiovascular disease, fatty liver and dental caries. Fructose is metabolized mainly in the liver, where high intakes can promote fat production and insulin resistance. Whole grains are associated with lower risk of cardiovascular disease, type 2 diabetes and colorectal cancer.