In obese women with polycystic ovary syndrome (PCOS), weight loss improves insulin resistance and hyperandrogenism, resulting in improvement of clinical symptoms. Weight loss is not required in lean PCOS patients; nevertheless, the influence of meal timing and composition on glucose metabolism and hyperandrogenism may have clinical value. In this study the investigators investigate the effects of two isocaloric diets with different meal timing distribution on insulin resistance and hyperandrogenism in lean PCOS patients.