Green Tea Extracts Helps in Weight Loss and Increase In Metabolism

There are two ways to lose weight -- either reduce energy intake, or increase energy expenditure. Because hypothyroidism -- even after treatment -- may reduce energy expenditure in some people, patients naturally are looking for options that can help safely help raise their metabolism.

In a study reported on in the American Journal of Clinical Nutrition, it was found that green tea extracts resulted in a significant increase in energy expenditure (a measure of metabolism), plus also had a significant effect on fat oxidation. While some of the effects were originally theorized to be due to the caffeine content of green tea extracts, the researchers discovered that the tea actually has properties that go beyond those that would be explained by the caffeine.

The same amount of caffeine as was in the green tea, administered alone, failed to change energy expenditure in other studies. This led reseachers to believe that there is some interaction going on with the active ingredients of green tea that promotes increased metabolism and fat oxidation resulting in weight loss.


The researchers indicated that their findings have substantial implications for weight control. A 4 percent overall increase in 24-hour energy expenditure was attributed to the green tea extracts, however, the research found that the extra expenditure took place during the daytime. This led them to conclude that, since thermogenesis (the body's own rate of burning calories) contributes 8 to 10 percent of daily energy expenditure in a typical subject, that this 4 percent overall increase in energy expenditure due to the green tea actually translated to a 35 to 43 percent increase in daytime thermogenesis.