Goishi tea leaf powder affects lower body weight and visceral fat accumulation during energy restriction in obese rats.

Goishi tea is a unique Japanese post-fermented tea produced in Kochi prefecture. The aim of this study was to investigate whether the supplementation of energy-restricted diet with Goishi tea leaves affects body weight, visceral fat accumulation, and fecal lipids in diet-induced obese rats. 18 male Wistar rats were fed a high-fat diet for 12 weeks. Subsequently, the diet-induced obese rats were fed a low-energy diet containing 1% (G1 group) or 3% (G3 group) of Goishi tea leaf powder, or without any tea extracts (C group) for 4 weeks. After 4 weeks, body weight and body fat ratio were significantly lower in the G3 group than in the C group. Plasma insulin levels were significantly higher in the C group than in the G1 and G3 groups, whereas plasma leptin levels were significantly lower in the G3 group than in the C group. In addition, the lipid absorption rate was significantly lower in the G3 group than in the C and G1 groups. In conclusion, the administration of Goishi tea leaves under dietary restrictions might contribute to body weight reduction and inhibition of lipid absorption, as a diet therapy to help prevent obesity and metabolic syndrome. J. Med. Invest. 70 : 60-65, February, 2023.