Don't toss that peel--it may help you burn fat. When scientists added ursolic acid (found in apple skin) to the high-fat diets of mice, the mice gained less weight.
"Ursolic acid ups muscle and brown fat, which boosts calorie burning," says lead researcher Christopher Adams, MD.
Other likely slimmers:
Pears: They're high in flavonoids and catechins, antioxidants that help women ward off weight gain.