Is Green tea good for weight loss? Does green tea "burn fat?"
Believe it or not, more and more often you'll find green tea (or green tea extract) included in the compilations of many of the more popular weight loss supplements today (interestingly, it may not be quite as good as oolong tea, reviewed here!)
And why are supplement makers so hasty to include green tea in their weight loss products?
Well, the benefits of green tea are numerous. In fact, if you were to go to PubMed.com and do a search for green tea, you'd find over 2,000 studies performed on green tea and its components (eg, epigallocatechin gallate (EGCG), theanine, etc). Possible benefits are being investigated for weight loss, cancer prevention, antioxidant activity, cognitive enhancement, general good health and well being... and the list goes on and on.
But why is green tea included in most popular fat burners today?
Many reasons. First of all, green tea extract is a source of caffeine, and is often used as the caffeine component of many popular fat burners. Caffeine, of course, is a decent fat burner with a well-established track record (see Am J Clin Nutr. 1989 Jan;49(1):44-50, Am J Clin Nutr. 1980 May;33(5):989-97).
That makes it a decent quality fat burner in and of itself. However...
If that's all green tea did, this would be a pretty short article. Luckily, it provides additional benefits -- far and beyond what plain caffeine could do. First, it's a powerful anti-oxidant. Yes... just like vitamin C and beta-carotene! But researchers have suggested that the active ingredient (called epigallocatechin gallate -- I kid you not!), may be up to 200 times more powerful than vitamin E as an oxidant.
But wait... that's still not the best part!
Green tea may be useful as a glucose regulator -- meaning it slows the rise in blood sugar following a meal.
It does this by slowing the action of a particular digestive enzyme called amylase. This enzyme is pivotal in the breakdown of starches (carbs), that can cause blood sugar levels to soar following a meal (see Am J Clin Nutr. 2006 Sep;84(3):551-5).
This is pretty exciting stuff -- along with a chromium, and possibly a vanadyl supplement, green tea might be the missing link in proper glucose management.
Green tea has also helped aid weight loss by increasing the metabolic rate, causing those who use it to experience greater calorie burn (American Journal of Clinical Nutrition. 1999 Dec;70(6):1040-5)
A recent study further validates green tea's effectiveness. Published in the American Journal of Clinical Nutrition (Am J Clin Nutr; 81:122-129), it indicated the ingestion of a tea rich in catechins (catechins are a major component of green tea extract) leads to both a lowering of bodyfat AND of cholesterol levels.
Additionally, green tea may inhibit fatty acid synthase (see Life Sci. 2004 Mar 26;74(19):2389-99, Int J Cancer. 2003 Oct 10;106(6):856-62 , Biotechnol Appl Biochem. 2006 Jan;43(Pt 1):1-7, Curr Med Chem. 2006;13(
:967-77).
Fatty acid synthase is an enzymatic system that is involved in the process of turning carbohydrates into fat. Early animal studies suggest the inhibition of fatty acid synthase can lead to dramatic weight loss.
If that weren't enough, there's also evidence that consuming green tea high in catechins reduces cardiovascular risks in addition to reducing body fat (Obesity (Silver Spring). 2007 Jun;15(6):1473-83).
In short, green tea's weight loss benefits are a result of several mechanisms.
As discussed, these include an increased metabolism, a positive effect on blood sugar and insulin regulation, and possibly the inhibiting of certain enzymes which are required for the processing of carbohydrates and fats. It also has been shown to lower LDL levels (that's the "bad" cholesterol) as well as triglyceride levels.
(See Mol Nutr Food Res. 2006 Feb;50(2):176-87, Am J Clin Nutr; 81:122-129, Journal of the International Association for the Study of Obesity. 2000 Feb;24(2):252-8, The American Journal of Clinical Nutrition. 1999 Dec;70(6):1040-5 -- for additional proof of green tea's weight loss effectiveness).
The combination of caffiene with green tea -- found in many popular fat burners -- also seems to encourage weight loss (Obes Res. 2005 Jul;13(7):1195-204), and therefore is a smart addition to any fat burner compilation.
In the past, I've supplemented with the Canadian formulation of MuscleTech's Hydroxycut (the older US version did not contain any green tea, although the new reformulated version does), which contains over 900mg of green tea extract per serving. In general, I found that blood sugar levels seem to be stable, cravings were minimal as were the jitters and shakes normally associated with ephedrine based products.
I'd say it was definitely helpful, but not earth-shatteringly effective. It was no "magic pill" I guess you could say. Proper diet and an effective exercise program will be key to wringing the most out of green tea fat burner.
Lately however, I've been making a point of drinking large amounts of both green and oolong teas on a daily basis. Although my own experience is definitely anecdotal, I truly feel it is making a difference. Although I am currently dieting and have increased my weekly cardio training, the weight seems to be coming off a lot faster than usual.
If you'd like to try green tea, you have a couple of choices...
1) Buy a popular fat burner which contains a good dose of green tea in its formulation. A couple of good products are Isatori's Lean System 7 (reviewed here) and Genuine Health Abs+ (reviewed here!)
2) Buy capsules of green tea: Most popular brands now provide green tea in this format now. It's pretty cheap, and best of all, it's easy and convenient! We like PrimaForce's Lean Green available at BodyBuilding.com, our recommended online retailer. It's a pretty potent product, standardized for 50% EGCG, and 60 caps sell for just over $10.
3) Drink green tea instead of regular tea or coffee. My current favorite way to capitalize on the health and fat burning benefits of green tea. And we're talking the loose stuff, here, not the bagged stuff found in the grocery store.
You really don't need to take a pill to get this stuff into your system. According to Julian Tai, a friend of mine from Amazing-Green-Tea.com, this is the optimum method of getting your daily dose of green tea. He claims that capsules and tablets run the risk of being contaminated with all sorts of nasty ingredients.
