Caffeine: Does it help you lose weight?

A few studies indicate that large amounts of caffeine — the equivalent of six cups of coffee a day — may slightly enhance weight loss in people who exercise and maintain a low-fat diet. But no studies indicate that weight loss from large amounts of caffeine is significant or permanent. There's also no evidence that increasing caffeine intake alone has any effect on weight loss.

Is caffeine an appetite suppressant? Yes, but this effect lasts only a very brief period — not long enough to lead to significant weight loss. Does caffeine increase your body's ability to burn calories? Maybe, but again, probably not enough to result in significant weight loss.

Caffeine does act as a diuretic, which means it causes an increase in the amount of urine you excrete. This water loss may decrease your body weight. But it doesn't decrease body fat. Also, keep in mind that caffeine is a stimulant that can increase your heart rate and blood pressure, interrupt your sleep, and cause nervousness and irritability. Also, many caffeinated beverages are high in calories, which can contribute to unwanted weight gain.