How the Green Tea Diet Works

Introduction
Lose 20 pounds in 20 days!" "Trim inches off your waistline with one easy pill!" With seemingly miraculous guarantees like these, who wouldn't want to give diet pills a try? But with so many diets, supplements and pills to choose from, it's easy to get overwhelmed by choices. What really works? What's worth your money? And, most importantly, what's actually safe and healthful to be putting into your body?

This last question -- and the fact that more and more studies are claiming certain supplements and chemicals can cause more harm than good to your body -- has been pushing people toward the use of gentler, more natural weight loss supplements. As a result, green tea has gained popularity as a safe, effective weight loss aid.
For centuries, certain cultures -- especially those in China and Japan -- have been drinking tea for its health benefits. Among tea choices, green tea has been especially noted for its positive antioxidant, anticarcinogenic and metabolic properties. Many of these benefits are due to its high amounts of polyphenols, especially a certain polyphenol called EGCG. Because they contain potent antioxidant properties, polyphenols are thought to help the body's immune system, protecting cells against disease-causing free radicals [source: University of Maryland Medical Center]. Thanks to this composition of chemicals, green tea has been said to protect against everything from cancer to high cholesterol to heart disease. And some even claim that EGCG may boost the metabolism, suppress appetite and even burn fat.

But will this healthful supplement really help you drop those pounds? Read on to find out how green tea is used in diet pills.

Green Tea Diet Pills
Name That Tea
Most teas we drink come from the same plant, Camellia sinensis. So how does one plant produce so many types of tea? It all has to do with the way the leaves are processed after picking. To make black tea, leaves are allowed to ferment, or oxidize -- this step of exposing the leaves to the air gives the tea its color. Green tea, on the other hand, is lightly steamed rather than fermented, so it retains much more of its polyphenols, which increases its antioxidant properties [source: University of Maryland Medical Center].
So how can an ancient beverage be used in a diet pill? Green tea diet pills use the same leaves that are used to make the drinkable green tea, but they are in a concentrated form. When a diet pill contains green tea extract, supposedly, the "extract" is the polyphenols from the green tea leaves.

In addition to EGCG and its benefits -- including increased metabolism -- green tea also contains caffeine, which is said to be a mild appetite suppressant. Caffeine is also said to speed up thermogenesis, which is the body's process of producing heat that leads to fat burning.

Though these benefits can be obtained through drinking green tea, some people would rather swallow a couple pills rather than gulp down cups and cups of a beverage every day. For those who do prefer the pill form, there are many varieties of green tea diet pills. Some pills contain 100 percent green tea extract -- these are basically just super-concentrated green tea. However, the majority of green tea diet pills also contain other weight-loss supplements, such as chromium or hoodia. When used in combination with these stronger appetite suppressants, these are said to be more effective, though additional research is needed to be certain.

When choosing a green tea diet pill, the important thing to look for is the amount of polyphenols, also called catechins, which the pill contains, since this is the main substance that gives green tea its weight-loss properties. If you're taking a pill that contains 100 milligrams of catechins twice daily, that's equivalent to about two cups of green tea. Is the pill worth it? Some experts suggest looking for a pill that contains 125 to 500 milligrams of polyphenols, though there is no established recommended dose [source: Pizzo].

How Diet Pills Work

OTC Diet Pills

Some over-the-counter pills (such as Xenedrine, Dexatrim and Zantrex-3) once used a powerful combination of the stimulant ephedra and caffeine to help users shed pounds. They reportedly worked in combination by increasing energy expenditure -- or thermogenesis (it is thought that caffeine increases metabolism by increasing the breakdown of fatty acids) -- and reducing appetite (ephedrine acts on the satiety center in the hypothalamus). But since late 2003, when the FDA banned the sale of ephedra-containing drugs due to evidence of increased risk of heart attack, these formulations have replaced ephedra with a mixture of vitamins (such as thiamin, riboflavin, vitamin B-6, folic acid), an ephedra-like substance called synephrine that is found in certain citrus fruits, and caffeine. The combination reportedly increases energy while boosting metabolism.

There are many herbal weight-loss supplements on the market today, and they utilize different mechanisms to reportedly aid in dieting. Here are some of the more common ingredients and their reported weight-loss mechanisms:

Herbal ephedra, caffeine, guarana and country mallow - Increase metabolism
Guar gum, glucomannan and psyllium - Cause a "full" feeling
Hydrocitric acid, green tea, conjugated linoleic acid and pyruvate - Slow fat production
Chitosan (or chitin - substance found in the exoskeleton of shrimp and other shellfish) - Block fat from being absorbed
So as you can see, there are a lot of diet pills out there, all claiming to help you lose weight in one way or another. But do they really work? And what kinds of side effects can you expect?