Exercise and green tea extract stimulate fat oxidation and prevent obesity in mice

The purpose of the present study was to explore the combined effects of dietary supplementation with green tea extract (GTE) and regular exercise on the development of obesity in high fat-fed C57BL/6J mice.

Weight and age-matched male mice were divided into 5 groups of 10 mice each. Groups were treated as follows: a low-fat diet and not exercised (LF), a high-fat diet and not exercised (HF), a high-fat diet supplemented with GTE and not exercised (GTE-HF), a high-fat diet and exercised regularly (EX-HF), or a high-fat diet supplemented with GTE and exercised regularly (GTEEX-HF). The exercise modality was treadmill running.

After 15 wk, GTE alone and regular exercise alone caused a 47 and 24% reduction in body weight gain induced by the high-fat diet, respectively, and when combined, resulted in an 89% reduction. In visceral fat accumulation, GTE alone, exercise alone, and their combination caused a 58, 37, and 87% reduction, respectively. Indirect calorimetry showed that the GTEEX-HF group had the highest energy expenditure and fat utilization in the sedentary condition after 4 wk. Furthermore, the GTEEX-HF group utilized more fat than the EX-HF group during exercise. GTE supplementation increased hepatic fatty acid oxidation both in the exercised and nonexercised groups. In addition, when combined with regular exercise, GTE supplementation also stimulated skeletal muscle fatty acid oxidation.

In conclusion, dietary GTE and regular exercise, if combined, stimulate fat catabolism not only in the liver but also in skeletal muscle, and attenuate high-fat diet-induced obesity more effectively than each alone in C57BL/6J mice.