Health reports on how to harness your metabolism, which determines how quickly and efficiently your body burns calories. 

One way to fire up the energy that your body uses to consume and digest food is to have some spicy food or green tea. "You'll get a teeny increase in your metabolic rate—we're talking maybe a bump of 1 percent for an hour. But these little changes add up over time," says Polly de Mille RN, MA, RCEP, CSCS, USAT, clinical director of the Tisch Sports Performance Center at HSS.

Everyone loses muscle as we age, and as we do, we also lose our calorie-burning power. "By your 70s, your resting metabolism may be 15 percent slower than it was in your 20s," says de Mille. "That's 15 percent less food you can eat without gaining weight."

Read the full article at Health.com.