Sugar is the generalized name for sweet, short-chain, soluble carbohydrates, many of which are used in food. They are
carbohydrates, composed of carbon, hydrogen, and oxygen. There are various types of sugar derived from different sources. Simple sugars are called
monosaccharides and include
glucose (also known as dextrose),
fructose and
galactose. The table or granulated sugar most customarily used as food is
sucrose, a
disaccharide. (In the body, sucrose hydrolyses into fructose and glucose.) Other disaccharides include
maltose and
lactose. Longer chains of sugars are called
oligosaccharides. Chemically-different substances may also have a sweet taste, but are not classified as sugars. Some are used as
lower-calorie food substitutes for sugar described as
artificial sweeteners.