Eat some hot peppers and you may feel like you’re burning up. But does that mean you’re burning more calories, too? Maybe. According to research, capsaicin – the substance that makes peppers like habanero, Scotch bonnet, jalapeno and cayenne so hot – may rev up your metabolism and help fight fat.

In a South Korean study published in the June 2010 Journal of Proteome Research, lab rats fed capsaicin lost 8 percent of their body weight, likely due to changes in proteins that break down fat. In another study, this one with humans at the University of Oklahoma, a capsaicin weight-loss supplement generated a 3 to 6 percent hike in energy expenditure among participants – a metabolism boost that researchers claim is equal to a 20-minute walk.

So, is capsaicin the new weight-loss magic bullet? Not at all, says registered dietitian and weight-loss expert Joanne Larsen. “Capsaicin does have some promise in increasing fat loss and changing abdominal fat distribution, but weight loss still depends on calories in minus calories out,” she says.

Further, the effects of the burn were short-lived. “The capsaicin only hiked metabolism for a few hours after the meal,” says Larsen. “Exercise helps increase it for 15 hours.”

The bottom line: Go ahead and eat your peppery meals as part of a reduced-calorie diet. There may be benefit. But don’t replace that daily 20-minute walk just yet.