Our bodies can only absorb monosaccharides or single sugars, which are the smallest sugar units. Most sugars found naturally in foods or added to foods are disaccharides, or double sugars. During digestion disaccharides are broken down by digestive enzymes into the individual monosaccharides which can be absorbed by the body. Starches or complex carbohydrates are polysaccharides, which contain hundreds of single sugars. For example, they give foods sweetness.
Sugars also play an important role in food preparation.
Besides improving the flavor of foods, they add texture and color to baked goods. Sugar also helps to thicken, firm, or preserve foods such as puddings, jams, and jellies. It is necessary for good health, growth, and proper body function and activity. Foods in the major Food Guide Pyramid food groups that contain natural sugars supply energy and also provide important vitamins, minerals, protein, and fiber. Sugar by itself and foods at the top of the Food Guide Pyramid which supply calories and large amounts of sugar but few nutrients are sometimes called empty calorie foods.