Complex carbohydrates are a type of carbohydrate consisting of long chains of sugar molecules. Some synonyms for complex carbohydrate include polysaccharides, starches, dietary fiber, and glycogen. Polysaccharides are large complex carbohydrates made up of many sugar units linked together. Starches are polysaccharides found in plants that provide energy for the body. Dietary fiber, also known as roughage, is another type of complex carbohydrate found in plants. It cannot be digested by humans, but it helps regulate digestion and promote satiety. Finally, glycogen is another type of complex carbohydrate found in animals and humans that serves as a stored form of glucose for energy. All of these synonyms refer to the same category of nutritious carbohydrates that are essential for a healthy diet.