How do low-calorie sweeteners affect your weight? It depends. Researchers randomly assigned 123 people who were overweight or obese to drink roughly 40 to 60 oz. a day of Kool-Aid sweetened with sugar, aspartame (Equal), saccharin (Sweet‘N Low), stevia extract (Truvia), or sucralose (Splenda). The sugar-sweetened drink supplied 400 to 560 calories. (Heavier participants got larger servings.) After 12 weeks, the sugar group had gained 4 pounds and the saccharin group had gained 2½ pounds. The stevia and aspartame groups gained—and the sucralose group lost—about 1½ pounds, but those changes weren’t statistically significant. Glucose tolerance didn’t change in any group.