Research shows that ursolic acid, a compound found in apples, may help fight obesity. The study by the University of Iowa in the US found that mice that ate a high-fat diet including ursolic acid developed more muscle and more brown fat than mice eating the same diet without the compound.

The more muscle you have, the more calories you will burn, which aids weight loss. And brown fat helps keep you trim because it burns energy, unlike white fat, which stores it.