Researchers from Germany performed a detailed study to examine the short-term effects of caffeine and two doses of EGCG on measures of fat burning.
In a double-blind cross-over study, obese men supplemented daily for three days with either a placebo, 300 mg of EGCG, 600 mg of EGCG, 200 mg of caffeine, or a combination of 300 mg of EGCG and 200 mg of caffeine.
On day three of supplementation, subjects rested quietly for eight hours while measures of fat oxidation were made before and after a standardized meal. Fasting measures of fat oxidation were increased for the low dose EGCG (8%), high dose EGCG (15%), caffeine (26%), and combined EGCG/caffeine (35%) trials. Measures of fat oxidation after the standardized meal were increased for the low dose EGCG (33%), high dose EGCG (20%), caffeine (35%), and combined EGCG/caffeine (49%) trials.
These findings support the use of about 300 mg of EGCG from green tea per day for increasing fat burning. Higher doses did not improve fat burning results. Short-term supplementation with either EGCG or caffeine alone showed positive effects, but the combination resulted in the highest rates of fat oxidation.