Objectives　The objective of this study was to investigate effect of the long-term intake of polyphenols derived from Japanese pagoda tree（enzymatically modified isoquercitrin）on body fat accumulation in overweight and obese subjects.
Methods　【The 1st study】A single-blind placebo-controlled cross over study was conducted on 21 subjects（16 men and 5 women）to evaluate energy metabolism during exercise.【The 2nd study】A double-blind placebo-controlled study was conducted on 200 overweight and obese subjects（102 men and 98 women）to evaluate body fat accumulation. They were randomly divided into two groups and ingested the beverage containing 0 mg or 275 mg of polyphenols for 12 weeks.
Results　【The 1st study】Fat oxidation increased significantly during exercise in test group compared to placebo group.【The 2nd study】Abdominal total fat area, visceral fat area, subcutaneous fat area and waist circumference reduced significantly in test group compared to placebo group. No adverse events related to the bevelages were obserbed in both groups.
Conclusions　These results suggest that the long-term intake of polyphenols derived from Japanese pagoda tree reduced body fat safely, and might be useful for prevention and improvement of obesity and metabolic syndrome.