That fiery sensation you get when you bite into a hot pepper? That is the work of a compound known as capsaicin. Consuming capsaicin revs up your metabolism and is associated with greater fat-burning power. For example, rats on a high-fat diet who are given capsaicin have greater activity of enzymes that metabolize fats (Kawada, Hagihara, & Iwai, 1986). Capsaicin may even be able to regulate your body’s longer-term control over metabolism, turning on and off certain genes that affect fat burning. In general, the hotter the pepper, the greater the amount of capsaicin it contains.