If it works for chubby rodents, it could work for you. Although most clinical studies testing the effects of green tea on weight loss include calorie-restricted diets, several studies involving mice and rats linked weight loss strictly to the antioxidants in green tea. The weight loss was minor, however, so don't expect green tea wipe out the weight from fried chicken and frosted cupcakes.
Fat-Burning Properties in Green Tea
Green tea contains two fat-burning properties: caffeine and catechins. Green tea contains far less caffeine than black tea or coffee, and most studies have concentrated on the role of catechins, an antioxidant that boosts metabolism. In a Rutgers University study, obese rodents fed catechins lost weight while maintaining a high-fat diet. Healthy rodents fed green tea antioxidants didn't gain weight, according to a report published in October 2008 in the "Journal of Nutrition."
Clinical Study
Studies involving humans have mainly focused on green tea as a supplement to calorie-restricted diets. In a study conducted by scientist, Kevin Maki, men who consumed 660 mg of green tea catechins lost 5.4 lbs. in 12 weeks while also following a diet that cut 500 calories from their diets. Men who drank black tea containing 22 mg of catechins lost 2.9 lbs. The weight loss that could be attributed strictly to green tea consumption would be 2 1/2 lbs. --- about 1 lb. a month.
How Much to Drink
You could theoretically achieve the 2 1/2 lb. weight loss attributed to green tea in Maki's study by drinking 6 cups of green tea brewed from fresh leaves daily, based on a study conducted by the United States Department of Agriculture. If you were to drink decaffeinated tea, you'd need to drink twice as much to attain the same effects and, if you chose to drink bottled green tea, you'd need to drink 55 cups a day, according to figures obtained from the USDA study.
Green Tea as Dietary Supplement
Green tea could supplement a healthy weight loss plan. The Mayo Clinic, for instance, offers a plan that provides for 500 fewer calories than you need to attain your current weight. Based on the USDA food pyramid, it provides unlimited amounts of fruits and vegetables and generous amounts of carbohydrates. Protein and dairy are slightly more restricted; the USDA says to restrict protein to 6 oz. daily for weight loss and keep fats and sweets to a minimum. You should lose about a 1 lb. per week on this diet or 5 to 6 lbs. a month if you included green tea in your diet.
Safety Considerations
Green tea has been consumed for centuries in China, where it is grown, and the only known side effects are those from caffeine. Pregnant women should probably drink no more than 2 cups of green tea daily, according to the "British Medical Journal." The journal, based on a four-year study, concluded that caffeine could cause babies to be born at lower than normal birth weights. Decaffeinated green tea should be a safe choice, but anyone with a preexisting health condition should consult a physician before embarking on a weight loss program based on reducing calories or drinking green tea.
References
- USDA: Brewing Up the Latest Tea Research
- "Biotech Business Week"; Scientists at Rutgers University publish new data on obesity; Bose, M., etal; Oct. 13, 2008
- "Biotech Business Week"; New Obesity Study Findings Have Been Reported by K.D. Maki and Colleagues; March 2 2009
- Mayo Clinic: The Mayo Clinic Diet
- BMJ: Maternal Caffeine Intake During Pregnancy and Risk of Fetal Growth Restriction; a Large Prospective Observational Study
Member Comments