A meta-analysis conducted into the effects of green tea on weight loss and weight management in Asian and Caucasian populations found that the average weight lost by participants across the studies was 1.3kg (95% CI: 0.57 to 2.05), when compared to the control groups.
This weight loss was due to the intake of catechins, the compound which also gives the tea its characteristic bitter taste. Interestingly, this study also found that moderate to high levels of caffeine intake (>300mg/day) diminished the positive effects of green tea on weight loss.
Another meta-analysis study looking at catechin rich teas, revealed that the combination of catechin-caffeine mixture resulted in a significant increase in fat oxidation, when compared to control and a caffeine only group. Fat oxidation is the rate at which fat is ‘burned’ or converted into energy to fuel metabolism. Again, demonstrating the ability of catechins to have a positive influence on the weight management, an issue many struggle with.