A growing number of cellular studies support the idea that
activates key metabolic pathways in thermogenesis and weight control. However, there are only a few studies that have examined whether the effects occur in humans. Researchers from Thailand conducted a study to determine the
effects of green tea on weight loss
. They also explored potential mechanisms of action by measuring body composition, energy expenditure, and hormone levels. Overweight subjects were randomized to receive a placebo or 250 mg
green tea capsules
at breakfast, lunch, and dinner (total 100 mg EGCG/day) over a period of 12 weeks. The study confirmed previous reports that showed greater weight loss with green tea supplementation. After only 4 weeks, green tea supplementation resulted in a 6 pound greater weight loss. By 8 weeks weight loss was 11 pounds greater with green tea. The greater weight loss was due mainly to a decrease in body fat. Food intake was not different, but resting energy expenditure was increased more with
green tea supplementation
, as was fat oxidation. The results show impressive weight and fat loss in a short time period of green tea supplementation and confirm the effect is mediated in part by an increase in thermogenesis.
Auvichayapat P, Prapochanung M, Tunkamnerdthai O, Sripanidkulchai BO, Auvichayapat N, Thinkhamrop B, Kunhasura S, Wongpratoom S, Sinawat S, Hongprapas P. Effectiveness of green tea on weight reduction in obese Thais: A randomized, controlled trial. Physiol Behav. 2008 Feb 27;93(3):486-91. Epub 2007 Oct 18.