Sugars are naturally occurring carbohydrates, and the simplest kind of carbohydrate. Sugars are a source of energy for your cells, form part of larger, more complex molecules, and provide energy storage. Since your body quickly digests sugars, they also provide you with a quick source of energy. There are three types of sugars.
Monosaccharides are simple sugars, meaning they have only three to seven carbon atoms arranged in either a chain or ring structure. The ‘mono’ stands for one, and signifies that monosaccharides only have one ring. Two kinds of monosaccharides include glucose and fructose. Glucose is the most important monosaccharide in nature; it is the main source of energy for body cells and is present in most sweet fruits, as well as in your blood. Fructose is the sweetest monosaccharide, present in fruits and honey.
Disaccharides are two simple sugars linked together in a double ring. Your body must break down disaccharides, just like any carbohydrate other than monosaccharides, before you can get energy from them. Maltose is a disaccharide. It consists of two glucose molecules, while sucrose consists of glucose and fructose.
Polysaccharides are large chains of simple sugars, consisting of many monosaccharides. Examples of polysaccharides include starch and glycogen, both of which consist of hundreds of glucose units and different types of bonds holding them together. Polysaccharides serve two main functions: storing energy that your body can use when external food supply is low and providing structural support and protection.
Simple and Complex Carbs
Monosaccharides and disaccharides are simple carbohydrates, while polysaccharides are complex carbohydrates. Simple carbohydrates are present mainly in fruits and milk, as well as in high-sugar foods like candy and sweets. Complex carbohydrates are in legumes, grains and starchy vegetables like potatoes, peas and corn. The National Institutes of Health suggests eating more complex carbohydrates, especially whole grains and beans, while limiting sugars from candy and sweets, which have little or no nutritional value.