Green tea plus exercise may speed up weight loss

Mice given decaffeinated green tea and regular exercise lost weight and improved their health after 16 weeks. Specifically, they reduced body mass by 27% (on average), reduced abdominal fat by 37%; reduced blood glucose level by 17%, plasma insulin level by 65%, and insulin resistance by 65%..

Neither green tea alone, nor exercise alone, produced such significant changes. The amount of green tea was a lot: the equivalent of 8-10 cups a day. Decaffeination may not be important; it was done to keep the effects of caffeine out of the study.

Green tea is thought to affect genes related to energy metabolism.

http://www.futurity.org/green-tea-exercise-may-boon-weight-loss/