Effect of PRF on glucose homeostasis in HFD-induced obese mice. The mice were fasted for 8 h before measuring blood glucose. (A) Fasting blood glucose levels; (B) oral glucose tolerance test (OGTT); (C) serum insulin levels; (D) HOMA-IR index. ND, normal diet; HFD, high-fat diet; OR, HFD + 15.6 mg of orlistat; PRF 50, PRF 100, and PRF 200, HFD + 50, 100, and 200 mg of PRF, respectively. The results are expressed as the means ± SDs (n = 7). The values with different letters (a–d) are significantly different (p < 0.05) from each other according to one-way ANOVA and Duncan’s multiple-range test.