Complex Carbohydrates contain many sugar molecules while simple carbohydrates contain only one or two sugars. Complex Carbohydrates are called polysaccharides. Poly means “many,” and thus polysaccharides are made of more than 10 sugar molecules. (Monosaccharides are the simplest forms of sugar meaning one molecule.)
There are three classes of polysaccharides: starch, glycogen, and most fibers.
Starch
Starch is the storage form of glucose in plants. Glucose is a single sugar used in both plant and animal tissues for energy. It is the main source of fuel for the cells. After cooking, starch becomes digestible for humans. Raw starch may resist digestion. Examples of starch foods are corn, potatoes, rice, beans, pasta, and grains.
Glycogen
Glycogen is made up of many glucose units (single sugar). It is made and stored by the liver and muscle tissues of humans. It is not considered a complex carbohydrate in foods.
Fiber
Fiber is indigestible matter that survives digestion in the small intestine and then reaches the large intestine. It is divided into two categories: soluble and insoluble. Soluble means it can be dissolved in water, and insoluble means it does not dissolve in water.
Soluble fibers are fermentable fibers. It is believed that these fibers decrease blood cholesterol and sugar levels thus lowering the risk of heart disease and diabetes II.
Insoluble fibers are non-fermentable, and it is believed that this type of fiber decreases the risk of constipation and colon cancer because it increases stool bulk and reduces transit time. This reduced transit time means shorter exposure to consumed carcinogens in the intestine which may lower cancer risk. Visit the Mayo Clinic examples of high-fiber foods.
Since our digestive system lacks the enzymes necessary to digest bonds found in oligosaccharides, one component of fiber in plants, oligosaccharides are not digested when they reach the colon and are fermented by bacteria producing gas. (Flatulence) Examples of foods are leeks, onions, asparagus, and beans. To combat this, Beano® is a popular product that contains enzymes to break down oligosaccharides preventing them from being used to produce gas.
Beano’s University of Gas: http://beano.net/university-of-gas#