Looking for an easy way to increase your metabolism and burn off more calories? Try drinking water. A study conducted in Germany showed that subjects who consumed 500 mL (2 cups) of water increased their resting energy expenditure by 30% after 10 minutes of consumption with the effect lasting up to 40 minutes. This study also found that the increase in calorie burning came from fat in men and from carbohydrates in women. The researchers speculate that consumption of 2 liters (8 cups) of water a day would additionally help burn off close to 100 kcal/day.

J Clin Endocrinol Metab. 2003 Dec; 88(12):6015-9