How Does Green Tea Help You Lose Weight?

You may have read that green tea helps you lose weight. You may even have read it in sources other than websites trying to sell you green tea. The USDA and Harvard School of Public Health both report findings that this drink can make a difference on the scales -- but not all of the ways it does so produce healthy, or sustained, weight loss.

Green Tea Basics

Asian teas come in three different varieties -- green, black and oolong. All three are made from the same plant, with the difference coming from how they are prepared between picking and drinking. Green tea is steamed or fried after picking, and is not oxidized or fermented like black tea. It's a traditional drink in Japan, Korea and China -- and popular throughout the western world as well.

Stimulant Effects

Green tea contains caffeine -- although not as much caffeine as black tea. Caffeine is a stimulant, a kind of substance that gives you a feeling of energy and pushes you to be more active. More activity means you burn more calories throughout the day. Since weight loss is largely a matter of burning more calories than you eat, this can produce weight loss results. Stimulants also suppress your appetite, meaning you will eat fewer calories as well.

Diuretic Effects

Caffeine is also a diuretic. It stimulates your body to urinate more frequently, and in greater volume. If you don't drink a lot of water to keep up, this will dehydrate you to the point where you lose enough water to make a difference on your bathroom scale. However, this is temporary weight loss. You'll put the weight back on as soon as you restore a healthy level of hydration.

Portion Control

Health experts including celebrity personal trainer Bill Phillips and CNN Health correspondent Melina Jampolis, M.D., agree that drinking a zero-calorie beverage like green tea before each meal can help you lose weight. The drink partially fills your stomach with a diet-friendly substance, and you eat less at each meal as a result. According to Jampolis, this alone can make a difference of more than 12 lbs. each year.