Polycystic ovary syndrome (PCOS) is a common gynecological endocrine disease and a major cause of anovulatory infertility in reproductive-aged women. From 2010 to 2020, it was found that the prevalence of PCOS in reproductive-aged women in China reached 7.8%, an increase of 65% over 10 years ago. Many of them are overweight or obese. Weight loss including diet modifications can significantly reduce reproductive and metabolic disorders of PCOS and is recommended as a first step in the treatment of overweight or obese women with PCOS. Many weight loss programs have been proposed, including calorie-restriction diet (CRD) intervention. Whether CRD intervention prior to ovulation induction therapy could improve live birth rates in overweight/obese PCOS women has not been illustrated.