Green Tea Benefits - Weight Loss Studies Prove Green Tea Helps Boost Metabolism

There are many known green tea benefits, including weight loss. But exactly how does green tea help people lose weight? There are many claims that green tea speeds up metabolism, enhances fat burning, and increases levels of exercise endurance. But are these claims supported by scientific evidence?

Many different studies, both with animals and humans, have shown a positive link between green tea and weight loss. In one animal study, green tea extract given to laboratory mice was found to reduce body weight by 49%. If combined with exercise, green tea reduced weight by an astounding 89%.

Green tea also suppressed appetite in laboratory rats. Researchers at the University of Chicago discovered that rats injected daily with green tea extract demonstrated loss of appetite and reduced their food intake by 60% after one week. This led to a 21% reduction in the rats’ body weight.

This weight loss may be a result the blood sugar–regulating properties of green tea. Antioxidants called catechins are believed to be responsible for regulating blood sugar levels. Control of blood sugar levels is important in weight loss to prevent spikes in insulin, which is the hormone responsible for fat storage. Green tea allows sugar to enter the blood stream more slowly after a meal, thus stabilizing blood glucose and insulin levels to help prevent body fat storage.

Human studies also have demonstrated a positive correlation between green tea and weight loss. In a Japanese study, 38 healthy Japanese adult males were split into a couple of groups, one receiving green tea extract and the other receiving a placebo. Results showed that those in the green tea extract group had a decreased BMI, bodyweight, body fat mass, waist circumference, and subcutaneous fat area after 12 weeks, unlike the men within the control group.

Another green tea weight-loss study looked at 10 healthy Japanese adult males who were at random assigned to one of three groups. They got a dose of green tea extract and caffeine, caffeine only, or just a placebo. The men who took the green tea extract plus caffeine were able to exercise longer and burn more calories than the men who got just a placebo or caffeine.

In addition, a study published in the American Journal of Clinical Nutrition showed that green tea increased metabolism by 4%. Exercise is a key element to weight loss. It allows people to burn more calories, have more energy and build more muscle, which further increases metabolic rate.

Though the exact mechanism for the weight loss effects of green tea is not yet clear, researchers have hypothesized that green tea has a thermogenic effect because of its high amount of catechin polyphenols. These catechin polyphenols, particularly epigallocatechin gallate, or EGCG, combine with the caffeine in green tea to increase exercise endurance levels. The EGCG stimulates the release of fatty acids, which are then used by liver and muscle cells for fuel. This, in turn, decreases the rate at which carbohydrates are used and enables people to work out longer. The longer people are able to work out, the more calories are burned, and therefore more pounds are lost.

Drinking green tea to lose weight over a period of time may help. However, green tea is not a “lose weight quickly” diet, and it should not be used it by itself if a person has a significant amount of weight to lose. However, by combining proper diet and regular exercise with the green tea benefits, weight loss will definitely come much easier. Drink 3–5 cups of green tea each day. It just may be easier to drop those extra pounds and enjoy life with more energy and vitality.