Carbohydrates, also known as saccharides or carbs, are biomolecules made up of carbon, hydrogen, and oxygen atoms, typically in a ratio of 2:1 hydrogen to oxygen, similar to water. They are essential macronutrients found mainly in plant-based foods and dairy products, serving as the body's primary source of energy. When consumed, carbohydrates are broken down by the body into glucose, which fuels cellular activities in the brain, muscles, and other tissues. There are three main types of carbohydrates: sugars (simple carbs), starches (complex carbs), and fiber (a nondigestible carb). Foods rich in carbohydrates include bread, pasta, beans, potatoes, rice, fruits, vegetables, legumes, and dairy products. Carbohydrates provide 4 calories per gram and play important roles in immune function, blood clotting, and maintaining metabolic health. However, consuming too many added sugars can increase risks of cardiovascular disease and other health issues, so emphasis is placed on eating whole grains, fiber-rich foods, and minimizing processed carbs.
