Sucrose, ordinary table sugar, is probably the single most abundant pure organic chemical in the world and the one most widely known to nonchemists. Whether from sugar cane (20% by weight) or sugar beets (15% by weight), and whether raw or refined, common sugar is still sucrose. Sucrose is a disaccharide that yields 1 equiv of glucose and 1 equiv of fructose on acidic hydrolysis. This 1:1 mixture of glucose and fructose is often referred to as invert sugar, since the sign of optical rotation changes (inverts) during the hydrolysis from sucrose to a glucose fructose mixture. We get our energy from the nutrients in food. The main sources of energy are carbohydrates (starches and sugars), fats and proteins. The body can be compared to an engine that converts the energy in food into the energy we need to live. Sugars and starches are forms of carbohydrate. Nutritionists recommend that about half of our energy should be supplied by carbohydrates. The majority of this should be from starchy foods like cereals, rice, potatoes, pasta or bread, with the remainder coming from sugars. During digestion (the process by which we break down food substances ready for absorption and use by the body) complex starchy foods are broken down into sugars.