Its a well-documented fact that weight is function of calories consumed and used through activity. Diet, being a tool to modify that balance, is key to weight loss. First and foremost, green tea offers the advantage of being a non-calorie containing alternative to high-calorie drinks. I can attest to the fact that, as opposed to black tea, the absence of tannins in green tea makes drinking it without sweetener more palatable. Having said all that, there is research to support the idea that green tea may help boost metabolism to further enhance weight loss. Thermogenic foods are those foods that take more calories to digest than they provide, thereby burning more calories. One study of green tea showed that consuming a combination of caffeine and epigallocatechin gallate led to greater calorie consumption than caffeine alone. Large scale meta-analysis have also supported the idea that the combination of catechins and caffeine leads to an increase in overall energy expenditure and rate of fat oxidation. Finally, a well-documented study in 2005 showed men that consumed teas rich in catechins had reductions in body fat and LDL levels.