They add body to yogurt. They help balance acidity in tomato sauces and salad dressings. Certain sugars also play special roles in foods. Invert sugar helps keep sucrose from crystallizing in candies. Corn syrup is used in some foods because it is less sweet than sucrose.
Sugars are a source of energy for the body.
During intense physical activity, they are the main energy source. There are no nutritional differences among sugars. The body uses all types in the same way. Simple sugars then travel through the blood stream to body cells. There they provide energy and help form proteins, or are stored for future use.