Time restricted feeding (TRF) has been emerging as a potential weight loss strategy that avoids major dietary changes but achieves strong effects. It also improves insulin sensitivity through increased human growth hormone. This effect helps to improve the root cause of weight gain and has additional benefits for women with PCOS.

Inclusion Criteria:

• PCOS as described by Rotterdam's criteria

Exclusion Criteria:

• endocrine disorders
• diabetic
• hypertensive
• Taking medications affecting weight or energy intake/energy expenditure in the last 6 months, including weight loss medications, antipsychotic drugs or other medications as determined by the study physician;
• The body weight fluctuated more than 5% in recent 3 months.
• Liver and kidney dysfunction: renal impairment, creatinine clearance rate < 30 mL/min/1.73 m2, transaminase increased, more than three times higher than the normal limit;
• History of serious cardiovascular or cerebrovascular disease (angina, myocardial infarction or stroke) in the past 6 months;
• History of thyroid diseases;
• pregnant
• Currently participating in weight loss programs or weight change in the past 3 months (> 5% current body weight)
• Patients who cannot be followed for 16 months (due to a health situation or migration)
• Patients who are unwilling or unable to give informed consent

females