Effects of COS on body weight, fasting glucose, intraperitoneal glucose tolerance test (IGTT), and area under curve (AUC) of IGTT in HFD-fed mice. C57BL/6J mice were fed with control diet (CD), high-fat diet (HFD), CD plus COS (1 mg/mL in drinking water), or HFD plus COS for five months. After the treatment, the (A) body weight and (B) fasting glucose were monitored. (C) The IGTT was also measured, and (D) the AUC of IGTT was calculated. Data are represented as the mean ± SD (n = 5). # p < 0.05 or ## p < 0.01, compared to the CD group; * p < 0.05 or ** p < 0.01 compared to the HFD group.