Any of a class of sweet,Soluble Carbohydrate,as sucrose,glucose,sucrose from sugar cane and sugar beets. 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.