Coffee is known to boost your metabolism but tea offers a double-whammy; the caffeine and unique catechins in tea help to rev up your metabolism and boost fat burning. Research shows that drinking tea will provide a slight boost to your metabolic rate and increase fat burning more effectively than if you had caffeine alone. Since tea is calorie-free and antioxidant-rich, choosing it instead of other sugary beverages will provide an extra diet advantage. For the best results, drink plain green or oolong tea several times a day. Green tea is great iced or hot, and with fresh herbs, like the minty recipe below.