Green tea extract is often marketed as a weight loss or “fat burning” supplement. Is it worthwhile? I get conflicting reports from the research I’ve run across.
One Taiwanese study showed no benefit to green tea extract:
AIMS: To examine the effect of green tea extract (GTE) on obese women and to explore the relationship between GTE and obesity-related hormone peptides. METHODS: A randomized, double-blind, placebo- controlled clinical trial was conducted from July 2006 to June 2007 in Taipei Hospital, Taiwan. Seventy-eight of 100 obese women aged between 16 and 60 years with BMI>27 kg/m(2) and who had not received any other weight control maneuvers within the last 3 months completed this study. . . . . . .
CONCLUSIONS: This study showed no statistical difference in % reduction in BW, BMI and WC between the GTE and placebo groups after 12 weeks of treatment. The intake of GTE (491 mg catechins containing 302 mg EGCG) for 12 weeks is considered safe as shown by the results.1
But a study from Birmingham, UK sounds more promising:
Background: Green tea consumption is reportedly associated with various health-promoting properties. For example, it has been shown to promote fat oxidation in humans at rest and to prevent obesity and improve insulin sensitivity in mice. Objective: We investigated the effects of acute ingestion of green tea extract (GTE) on glucose tolerance and fat oxidation during moderate-intensity exercise in humans. . . .
Conclusions: Acute GTE ingestion can increase fat oxidation during moderate-intensity exercise and can improve insulin sensitivity and glucose tolerance in healthy young men.2
Where does this leave us?
It seems green tea extract may help with fat oxidation and insulin sensitivity. It isn’t too expensive (if you buy the right brand), and it is a good source of antioxidants.
In other words, it may be worth a try if you are implementing a diet and exercise program. PrimaForce Lean Green looks like a pretty good deal (I’ve had good experiences with that brand), but you can shop around. Or you may just want to buy some green tea–drink it down the old fashioned way.
Reminder: Fat loss happens because you have created a calorie deficit—not because you choose to use a particular supplement. You’ll need to be following a good program in order to lose fat. You may want to consider intermittent fasting if you are looking for an effective dietary strategy.
References:
1. Clin Nutr. 2008 Jun;27(3):363-70. Epub 2008 May 12. Effect of green tea extract on obese women: a randomized, double-blind, placebo-controlled clinical trial.
2. American Journal of Clinical Nutrition, Vol. 87, No. 3, 778-784, March 2008 Green tea extract ingestion, fat oxidation, and glucose tolerance in healthy humans
