Green Tea and Weight Loss – 2 Human Studies
Green tea is the second most popular beverage in the world, second only to water. Although black tea has been the type of tea most popular in the West, green tea is now gaining more ground as study after study reveals just how healthy this drink is. However, green tea has been the favorite beverage in Asia for at least a few thousand years, and at least a 100 million Asians drink this beverage daily!
Although the amazing antioxidant levels of this beverage are shown to help protect us from heart disease(1) and cancers(1,2,3), green tea’s real surge in sales in the West can, in large, be a direct result of its scientifically shown ability to aid in weight loss. If you have been looking into natural ways or looking at natural supplements that can aid with weight loss then you have more than likely heard about green tea and weight loss. However, for its weight loss effects, green tea is more commonly used in its supplement form, called green tea extract, rather than as a beverage.
The results of two Japanese studies brought to light how effective using green tea for weight loss is, and both studies revealed that it’s a type of antioxidant in green tea that brings about these weight loss properties. This antioxidant is called EGCG and it is one of a group of antioxidants found in green tea collectively known as catechin polyphenols.
The first study, which was undertaken in 2005, split a group of 30 overweight Japanese men into 2 halves. Over a period of 12 weeks, one group were given a daily beverage containing a standardized dose of 690mg of catechins, and the other group a beverage containing just 22mg of catechins, with both groups given the exact same diet plan. At the end of the 12 weeks the group given 690mg lost significantly more weight, including belly fat and total BMI than the group given just the 22mg.(4)
The second study, undertaken in 2008, investigated the effects of catechins upon overweight and obese participants over a period of 12 weeks. During this period all participants consumed the same amount of calorie intake and performed 180 min of supervised cardiovascular exercise each week. However, one half of the group were given a daily beverage of 625mg of catechins with 39mg of caffeine, and the other half a beverage containing 39mg of caffeine and no catechins. Again the results were greatly in favor of the group given the catechins, who lost more total body weight and significantly more abdominal fat than the group given no catechins.(5)
What the Results Tell Us
What we can take away from both studies is that using green tea catechins with diet and/or exercise can speed up the weight loss process, since in the first study the participants were dieting (but not exercising) and that in the second study participants were exercising and dieting. So essential the results are telling us that green tea weight loss really does work, but only in conjunction with a healthy diet and/or exercise plan. I guess more studies are needed to test the effects of green tea weight loss without changes to diet and physical activity levels.
Also, belly fat in particular appears to respond exceptionally well to green tea catechins and their weight loss effects. In fact the study in which those who exercised and were given the higher doses of catechins lost a greater percentage of belly fat than those in the study that dieted only but were given the high doses of catechins, even though they still lost a considerable amount of belly fat all the same!
Fortunately the dosing of catechins was very clear in both studies and we can see that if we want to achieve the same effects as the participants we need to take in between 625mg and 690mg per day of catechins (and diet!).