Aspartame
 

AKA: Equal, NutraSweet
Calories: 0
Found in: Drinks, gum, yogurt, cough drops

The deal: One of the most studied artificial sweeteners, aspartame has been accused of causing everything from weight gain to cancer.

However, since being approved by the FDA in 1981, studies have found no convincing evidence and the FDA, the World Health Organization, and the American Dietetic Association say aspartame in moderation poses no threats.

The CSPI feels differently, and gave it their lowest ranking in a review of food additives. People with phenylketonuria, an inherited genetic disorder, should avoid it.