Green tea and obesity: Effects of catechins on the energetic metabolism

Obesity is a metabolic disease which has now reached epidemic proportions, becoming a major health, social, and economic problem worldwide. Untreated obesity is associated with decreased quality of life and is a significant risk factor for the development of other serious health problems, such as diabetes and cardiovascular diseases. For this reason, new approaches to prevent excess body mass and to support its reduction if necessary are being examined. Catechins extracted from green tea – especially epigallocatechin gallate (EGCG) – are one of the most widely investigated biologically active substances. In addition to the antioxidant, anti-inflammatory, and anticarcinogenic properties of the catechins, they also exhibit a role in maintaining normal fat mass and body mass. There are numerous research studies showing that regular green tea consumption is associated with lower body mass, BMI, and waist circumference. In vitro and animal experiments confirm beneficial effects of catechins on the energetic metabolism. These compounds lower lipid and carbohydrates absorption in the intestine. Additionally, they affect the energetic metabolism, lowering the rate of lipogenesis and adipogenesis, while stimulating lipolysis and fatty acid oxidation, and increasing energy expenditure. Moreover, it has been established that green tea catechins have an effect on the glucose uptake in the insulin-dependent manner – by GLUT4. The aim of the following paper was to review and summarize the literature data concerning the role of green tea catechins in the prevention and treatment of obesity.