Try the hot, spicy kind you find in Asian import stores, specialty shops and exotic groceries. Dr. Jaya Henry of Oxford Polytechnic Institute in England, found that the amount of hot mustard normally called for in Mexican, Indian and Asian recipes, about one teaspoon, temporarily speeds up the metabolism, just as caffeine and the drug ephedrine do.
“But mustard is natural and totally safe,” Henry says. “It can be used every day, and it really works. I was shocked to discover it can speed up the metabolism by as much as 20 to 25 percent for several hours.” This can result in the body burning an extra 45 calories for every 700 consumed, Dr. Henry says.