Research has been conducted over the last few years to identify what compound present in green tea makes it a potent health drink. The scientists have found that green tea contains several antioxidants which are responsible for many of green tea's health benefits, including weight loss benefit.
A research study by American and Swiss scientists on the weight loss benefit of green tea was concluded and the results of which were published in the American Journal of Clinical Nutrition and Urology. During the course of their study, they have found that green tea contains certain compounds that contribute to its weight loss benefit.
Lead researcher, D. Abdul Dulloo said in a press release that there are only two ways to achieve weight loss - either reduce energy intake or increase energy expenditure. Green tea, it seems, has compounds that can increase the body's normal metabolism rate, thus giving it its weight loss benefit.
At the University of Geneva, where the study was conducted, Dr. Dulloo and his colleagues experimented on ten healthy young men. They theorized that the main contributor to green tea's weight loss benefit is its caffeine content. To test this hypothesis on green tea's weight loss benefit, they placed the study's participants on a typical "Western" diet which is about forty percent fat, thirteen percent protein, and forty-seven percent carbohydrates.
Thrice everyday, the researchers measured their subjects' energy expenditure (the measurement
used in determining the number of calories burned in 24 hours) and monitored their respiration quotient to find out how well they utilized their carbohydrates, proteins, and fats.
When they interpreted the data they collected, they found out that the men receiving regular dosages of green tea extract showed a significant increase in their 24-hour energy expenditure and a reduction in their respiration quotient (which means that more fat is burned, thereby achieving maximum weight loss). On the other hand, those men who were only given caffeine or placebo with every meal showed only minimal increases in their metabolism rates.
The scientists construed that the substance catechin polyphenol present in green tea adds to its weight loss benefit. These substances in green tea may alter how the body uses the hormone norepinephrine which is responsible for increasing the metabolism rate, thus leading to weight loss.
In their conclusion, the scientists inferred that green tea owes its weight loss benefit to the presence of antioxidants and the substance catechin polyphenol. These substances help increase fat and calorie burning and optimize weight loss.