Diurnal EE was higher during treatment with the green tea extract than during treatment with placebo or caffeine, by 4.5% and 3.2%, respectively, but significantly so only for the green tea extract. Total 24-h EE with the green tea extract, however, was significantly higher than that with both the placebo and caffeine, by 3.5% and 2.8%, respectively.
EE is Energy Expenditure. In other words, green tea helps raise your metabolic rate about 4% so you burn more calories — beyond the few calories the caffeine in the tea induces.
Makes it worth being a daily noncaloric beverage choice!