Feasibility Effects of a Low-GI, High-fibre Diet in PCOS: a Prospective Cohort Study in Remote Yunnan

Inclusion Criteria: * PCOS diagnosis will follow the Rotterdam criteria (presence of two of the following three features: oligo-/anovulation, clinical/biochemical hyperandrogenism, and polycystic ovarian morphology, with exclusion of related disorders). Additional inclusion criteria comprise: body mass index (BMI) ≥24 kg/m² (Chinese obesity threshold), stable weight for at least 3 months prior to enrollment (±2 kg), willingness to maintain current physical activity levels throughout the study period, and residence within the designated study area for a minimum of 6 months. Exclusion Criteria: * pregnancy or lactation; type 1 diabetes or type 2 diabetes; thyroid dysfunction, hyperprolactinemia, congenital adrenal hyperplasia, Cushing's syndrome, androgen-secreting tumors, or other endocrine disorders affecting metabolism; use of hormonal contraceptives, insulin sensitizers, or anti-obesity medications within the past 3 months (e.g., metformin, GLP-1 receptor agonists, systemic corticosteroids, hormonal contraceptives, anti-androgens). Severe hepatic/renal/cardiovascular disease; gastrointestinal disorders incompatible with high-fiber diets; history of bariatric surgery; current participation in other dietary intervention programs; and individuals with cognitive impairment or language communication barriers who cannot comprehend the study procedures or provide informed consent. Participants will be required to maintain their habitual physical activity levels during the intervention period and must not initiate new weight-loss medications/supplements; any deviations will be documented as protocol violations