Often sold for consumption as a beverage, green tea is also aggressively marketed as a tool for weight loss in the form of supplement pills. Although there is some evidence pointing to green tea's effectiveness as a weight loss tool, there is currently not enough information for the FDA to confirm this property. There are, however, some factors to consider that point to green tea as a positive addition to diet and exercise for weight loss, and also information on its value as a nutritional supplement.
Green Tea and Weight Loss
Green tea is simply the steamed leaf of Camellia Sinsensis, the tea plant from which other teas such as black and oolong are made, reports according to the National Center for Complimentary and Alternative Medicine. It has been used widely for weight loss, among other purposes. According to the National Institutes of Heath, study results are mixed when it comes to green tea as a weight-loss aid, and additional research is needed to verify this property of the tea. However, the ingredient in green tea that is most likely responsible for any weight-loss properties is caffeine. A cup of green tea typically contains about 50 milligrams of caffeine (equivalent to about a half-cup of coffee). However, caffeine is present at far higher levels in the green tea extract pills that are available on the market.
Extract Pills and Caffeine Content
The National Center for Complimentary and Alternative Medicine reports that green tea extracts have varying levels of caffeine content. A green tea extract pill can contain 100 to 750 milligrams of caffeine per capsule. That's the equivalent to one to seven-and-a-half cups of coffee. Whether caffeine consumption as delivered through green tea or its extracts helps weight loss is still unclear. Dr. Katherine Zeratsky of the Mayo Clinic states that there is no real evidence to support caffeine's role in weight loss. It is, however, a stimulant, and this property may cause increased energy, at the price of potential side effects like irritability, nervousness and insomnia. Green tea extracts that contain high levels of caffeine may also produce a diuretic effect--an increase in urination--potentially resulting in a temporary loss of water weight.
Additional Benefits of Green Tea
So, the potential of green tea for weight loss seems to rest mainly on its caffeine content. However, there are some well-studied beneficial effects of green tea that may contribute to overall health, thus promoting possible weight loss as a result. Green tea is known to increase mental alertness (likely due to the caffeine content), and is thought to lower cholesterol levels in the body. An alert mind and healthy cardiovascular system are conducive to beginning a program of exercise, which--unlike green tea--has been proved by U.S. agencies, such as the NIH, to promote healthy weight loss. Consuming green tea seems to have additional benefits. The NCCAM states that laboratory studies link consumption of green tea to protection against certain types of cancer, stemming from a chemical called ECGC contained within the tea. In addition, the NCCAM supports studies concerning green tea's positive impact on diabetes and heart disease. Green tea may very well be a tool for weight loss--if a bit limited by its active ingredient for this purpose--as well as a general recipe for good health.