Green Tea Useful in Weight Management

Low-dose green tea improves fat oxidation in obese men, according to a new study. Based on data from the National Health and Nutrition Examination Survey (NHANES), the Journal of the American Medical Association reports that the prevalence of obesity in the United States is increasing; it is currently estimated that 68 percent of American adults are overweight, which is defined as a body mass index (BMI) of 25 or greater. In addition, approximately 32.2 percent of adult men and 35.5 percent of adult women are obese, which is defined as a BMI of 30.0 or greater.

In this recently published clinical trial, healthy overweight or obese males were supplemented with epigallocatechin-3-gallate (EGCG), which is the main green tea catechin. The subjects received one of 5 different dosages daily for 3 days including a low dose (300 mg) of EGCG; a high dose (600 mg) of EGCG; 200 mg of caffeine; 300 mg of EGCG plus 200 mg of caffeine; or a placebo in successive intervals. After the third day of each supplementation regimen, the subjects were evaluated for oxygen consumption and carbon dioxide production to determine fat oxidation (the process of using fat for energy) after an overnight fast and after ingestion of a standardized test meal. The same subjects received these various supplementation regimens with a washout period of 7 days in between each of the treatments.

The results showed that during the first 2 hours after completion of the overnight fast, fat oxidation increased by 7.7 percent in the group supplemented with low-dose EGCG and by 15.2 percent in the high EGCG group compared to placebo, although these results were found to be statistically insignificant. However, caffeine plus EGCG increased fat oxidation by 35.4 percent compared to placebo during the first 2 hours after completion of the overnight fast. Caffeine supplementation alone increased fat oxidation by 26.3 percent during this two-hour time interval

More significant was the finding that during the first 2 hours after the test meal, low-dose supplementation with EGCG resulted in a 33 percent increase in fat oxidation while high-dose supplementation resulted in a 20.2 percent increase compared to placebo. Furthermore, the group receiving caffeine alone showed a 34.5 percent increase in fat oxidation and the administration of caffeine plus EGCG increased fat oxidation by 49.4 percent during the 2 hours after eating compared to the placebo group.

The study authors concluded, “Low EGCG increases postprandial [after meal] fat oxidation in obese men and this to the same extent as 200 mg caffeine, whereas high EGCG does not exert this effect.”

Reference:

Thielecke F, Rahn G, Böhnke J, Adams F, Birkenfeld AL, Jordan J, Boschmann M. Epigallocatechin-3-gallate and postprandial fat oxidation in overweight/obese male volunteers: a pilot study. Eur J Clin Nutr. 2010 Apr 7. Published Online Ahead of Print.

Individuals who do not want to consume large amounts of green tea as a beverage can take Green Tea Extract capsules. The Green Tea Extract capsules available here are very low in caffeine and are high in EGCG, an antioxidant polyphenol compound thought to be responsible for many of green tea’s significant health benefits.