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The positive effects of green tea on health have been demonstrated by several scientific studies. Green tea can help prevent cardiovascular diseases and the polyphenols can reduce cholesterol buildup in the blood vessels. Additionally, this tea also aids in sharpening and making the brain more alert.
But there are even more benefits. Green tea can have a positive effect on weight loss. How exactly this happens and how much tea you need to drink for it is explained below.
Green tea as fat burners
Green tea (extract) is one of the few truly effective and legal fat burners along with caffeine. Although the research is not entirely consistent, most studies seem to support this conclusion. However, the extent to which it actually contributes to reducing body fat seems to be limited.
What is green tea?
First, let’s distinguish between the different types of tea, black, green, and oolong. They are actually derived from the same type of tea leaves. The different tea plants, country of origin, and other influences determine the taste. However, the processing method of the leaves determines the type.
During the processing of black tea and oolong, the leaves are dried in the open air where they react with oxygen. This process is called oxidation. It causes the leaves to lose their green color and acquire a dark, golden brown color. With green tea, on the other hand, the leaves are briefly steamed instead. This kills enzymes needed for oxidation, preserving their green color. Consequently, the tea made from them retains a green color as well.
Due to this oxidation process, the tea loses a large portion of its polyphenols. For example, green tea contains almost 40 percent polyphenols, while black tea contains less than 10 percent. These polyphenols are responsible for the positive health properties. These polyphenols are not only found in tea but also in herbs, fruits, vegetables, and nuts. Polyphenols are essentially chemical compounds and act as antioxidants.
Within the polyphenols of green tea are the so-called catechins, which in studies on laboratory animals had very positive effects on the prevention of certain forms of cancer by neutralizing free radicals. Extensive research is still being conducted on the positive effects of catechins in humans.
Polyphenols, catechins, ECGC
The beneficial effects of tea are often attributed to catechins, a subcategory of polyphenols. These are found mainly in green tea and to a lesser extent in black tea. The most powerful and researched catechin is epigallocatechin gallate (EGCG). This catechin can prevent the growth of fat cells by inhibiting the enzyme that breaks down the hormone norepinephrine. Norepinephrine plays a role in the breakdown of fat cells. The net effect is that the breakdown of fat is accelerated, making it more readily available for energy expenditure.
Green tea as fat burner
Research seems to show that green tea can indeed contribute to fat burning, but the effect is limited. According to studies, the use of green tea can lead to the combustion of an extra 70-100 kcal per day. This corresponds to about 3-4 kg of body fat in one year. However, this effect is highly dependent on individual differences and the dose used. The body seems to adapt relatively quickly to the intake of green tea, reducing its fat-burning effect over time.
Green tea as fat burner: Long term effect
Although the fat-burning effect of green tea seems to diminish over time, it is believed that long-term consumption can still have a positive effect on body composition. This is because it can slightly increase energy expenditure and fat oxidation, even if these effects diminish over time.
Research reliability?
The reliability of research on the effects of green tea on fat burning is sometimes questioned because of methodological issues. Some studies show a strong effect, while others show none at all. Part of this discrepancy may be due to differences in the doses used and the duration of the study. Moreover, individual differences in metabolism and absorption of the active substances in green tea can also play a role.
Satiety and satiation
Finally, green tea may also contribute to weight loss indirectly by affecting satiety and satiation. Some studies suggest that the catechins in green tea can reduce appetite and increase satiety, leading to reduced calorie intake.
