What it is: The compound that gives hot peppers their kick.
How it works: Although the weight-loss benefits of the compound in pill form have not been confirmed, eating fresh chilies or ground red pepper (including cayenne) could turn on your body’s fight-or-flight response. “Because your body perceives that it’s under stress, it burns more calories,” says Mary-Jon Ludy, an assistant professor of clinical nutrition at Bowling Green State University, in Bowling Green, Ohio. It’s no bonfire, but you might burn about 10 more calories after eating a meal that contains capsaicin than after eating a meal that doesn’t—and eat about 50 fewer at your following meal.
Good to know: As little as one-quarter teaspoon of red pepper may do the trick at first. But if you consume the hot stuff regularly, you might need greater amounts to get you going, says Ludy.