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:

Bergamot oranges: Studies show that compounds in the fruit may decrease cholesterol and help with weight loss.

Blueberries: This superfruit may reduce belly fat by affecting fat-burning and storage genes, says a recent study.

Pears: They're high in flavonoids and catechins, antioxidants that help women ward off weight gain.