As with so many overnight sensations, the Perricone Prescription – more widely known as the green tea diet – came to worldwide attention on the Oprah Winfrey Show. Oprah's guest was the highly respected Dr. Nicholas Perricone, writer of several books, including the Perricone Prescription that described the medical research behind the amazing fat burning properties of green tea.

During his appearance on the Oprah Winfrey Show, Dr. Perricone claimed that replacing coffee with green tea could produce weight loss of 10 pounds in 6 weeks. Incredulous as it sounds, is it really possible to lose weight with tea alone? According to Dr. Perricone (and we have found numerous medical research studies back this up), the tea contains chemicals that perform at least 3 functions in the body that encourage weight loss.

1. Regulates blood sugar and insulin levels. Sharp spikes of insulin signal the body to store fat. As Dr. Perricone puts it, "elevated insulin puts a lock on body fat." Coffee, on the other hand, contains an ingredient that raises blood sugar and, in turn, insulin levels. Green tea regulates blood sugar itself, preventing the production of excess insulin. "If you do nothing else but substitute coffee with green tea, your insulin levels will drop and you will lose weight," says Dr. Perricone.
2. Promotes metabolism. The American Journal of Clinical Nutrition released a medical study in which metabolism rates were elevated by 4% in a 24 hour period. A phytochemical in green tea raises thermogenic activity in the body (the rate at which your body burns calories). This phytochemical also increases oxidation of body fat (the burning of fat cells).
3. Reduces appetite. Weight loss of 21% of body weight was observed in laboratory mice in a University of Chicago study. The researchers deemed that the fat loss was due to substantial loss of appetite and reduced calorie consumption. While Dr. Perricone has not mentioned appetite suppression as a benefit of green tea, several other studies have also claimed this theory.

Green tea boasts numerous other health benefits, which may not directly impact weight loss, but which are good health tonifiers. It has been found to trim cholesterol levels, lower high blood pressure, prevent a variety of cancers and prevent or reverse liver injury.

Dr. Perricone's tea diet has made a big splash on the dieting scene. Dr. Perricone and Oprah unknowingly let loose another fad diet waiting to happen. The internet has seen a blistering rise in weight loss products, like the acai berry diet phenomenon. Fad diets should be viewed with caution, especially when pricey products touting quick results are being tendered. Fad diets can be hazardous to the consumer not only by their high cost and inspirational promises, but also by being rough on the body. Rapid weight loss plans and crash diets are typically unsustainable (the weight loss will eventually come back) and can put the body into one of many nutritional imbalances that can do the dieter far more harm than good.

Dr. Perricone's tea diet is not a weight loss miracle as the weight loss industry would have you think. Nonetheless, this in no way diminishes the fact that it can be a fantastic addition to your weight loss diet plan. Dr. Perricone's advice to substitute coffee with green tea is a wonderful piece of health wisdom. His assertion that a tea diet by itself can effect rapid weight loss is, unfortunately, a disservice to the millions of dieters who are waiting for a magic bullet.

Bottom line: Yes, go get some green tea. Look for low cost bagged tea products or bottled green tea extract ($ 8 per bottle). It has relatively low levels of caffeine, so it is safe to drink (diluted) through the day. If you are looking to lose weight, do not fall for the idea that the green tea will do it for you. Real, lasting and safe weight loss only results from dietary changes and regular exercises.