Humans need carbohydrates in the largest amounts. Carbohydrates are incredibly important to the diet for many reasons.
For starters, carbohydrates are easily metabolized, which just means chemically broken down, and used as the body’s main fuel source. All of our bodily tissues have the ability to use the simple carbohydrate, glucose, as energy. When the body uses carbohydrates for energy, it can use other macronutrients for other jobs, like tissue growth and repair.
The brain, kidneys, muscles and heart all need carbohydrates to function properly, and carbohydrates aid in the synthesis of certain amino acids. Furthermore, fats can only be properly metabolized when carbohydrates are present and indigestible carbohydrates, in the form of fiber, are necessary for intestinal health.
Carbohydrates are primarily found in starchy foods, like grain and potatoes, as well as fruits, milk, and yogurt. Other foods like vegetables, beans, nuts, seeds, and cottage cheese contain carbohydrates, but in lesser amounts. Carbohydrates can be simple or complex, which refers to their chemical structure. Simple carbohydrates taste very sweet (like fruit sugar), while complex carbohydrates taste savory (like starch in potatoes).
Fiber is an indigestible form of carbohydrate. Since humans cannot break down fiber carbohydrates, they pass through the digestive system whole and take other waste products with them. Diets low in fiber have problems with waste elimination, constipation, and hemorrhoids. Diets high in fiber have shown decreased risk for obesity, high cholesterol, and heart disease. Fruits, vegetables, and whole grain products all contain high amounts of fiber.