Disaccharides include lactose and maltose ... The main one in human body is lactose. The purpose of disaccharide is to store energy. Starch belongs to polysaccharide, which will only be stored and absorbed if it is hydrolyzed into disaccharide or monosaccharide by enzyme. Glycogen is a form of disaccharide stored in human body. When the human body's energy consumption reaches a certain level, glycogen begins to play a role in supplementing insufficient energy and maintaining normal physiology.