Doctors in an obesity study said that earlier research had shown green tea increased fat-burning capacity and wanted to see if epigallocatechin-3-gallate (EGCG), the main catechin in green tea, would do the same. The body stores fat for sustained energy, but when the body does not regularly metabolize these fat stores, fat accumulates. In the study, 10 healthy overweight or obese men took EGCG with or without caffeine, caffeine alone or a placebo. After three days, the men fasted overnight and then ate a standard meal. Two hours after the meal, researchers measured fat-burning capacity. Compared to placebo, those who had taken a 600 mg dose of EGCG burned 20 percent more fat, and those who had taken 300 mg of EGCG—a lower dose—burned 33 percent more fat.