Low-calorie sweeteners provide sweet taste without energy (calories), or with very few calories. Most low-calorie sweeteners are not digested by the body and provide no calories. An exception is aspartame, which is metabolised naturally. However, since aspartame is approximately 200 times sweeter than saccharose (sucrose), only a tiny amount of aspartame (1/10 of a calorie) is needed to equal the sweetness of a teaspoon of sugar (16 calories). Low-calorie sweeteners are also called "non-nutritive sweeteners," "intense sweeteners," "high intensity sweeteners," "high potency sweeteners," or "alternative sweeteners".