Time-Restricted Eating as a Dietary Intervention for Polyendocrine Metabolic Ovarian Syndrome (PMOS): Protocol for a Randomized Controlled Trial

Background: Time-restricted eating (TRE) appears to be a promising dietary strategy for women with polyendocrine metabolic ovarian syndrome (PMOS), with potential benefits for insulin resistance and metabolic health. Emerging evidence also suggests that TRE may be associated with changes in gut microbiota composition and microbial metabolites, as well as circulating biomarkers involved in metabolic regulation. However, the relationships among these factors remain poorly understood. Objective: The aim of this study is to test the hypothesis that adding TRE to Healthy Eating Plate recommendations is more effective in improving insulin resistance, assessed using HOMA-IR, than Healthy Eating Plate recommendations alone in women with PMOS. Exploratory analyses will investigate changes in gut microbiota composition, microbial metabolites, and circulating concentrations of neuroactive compounds. Methods: This two-arm, parallel-group randomized controlled trial will compare 8-h TRE with unrestricted meal timing in women aged 18 to 40 years with PMOS and a BMI of 25–40 kg/m2 with a 1:1 allocation ratio. Both groups will receive Healthy Eating Plate-based dietary advice and attend four visits; the TRE protocol will be followed for 8 weeks. The primary outcome will be a change in HOMA-IR from baseline to week 8. We will also assess changes in glucose and lipid metabolism, circulating neuroactive compounds, including GABA and kisspeptin, anthropometric parameters, hormonal profile, composition and diversity of the microbiota and its metabolites. Discussion: We anticipate that this study will expand the limited evidence regarding TRE in women with PMOS and provide exploratory insights into the relationships among gut microbiota composition, microbial metabolites, circulating GABA and kisspeptin, and insulin resistance. The findings may help identify potential mechanisms underlying the metabolic effects of TRE in this population. Protocol version: 1.1, August 2026. Trial registration number: NCT06204965. Trial status: Participant recruitment has not yet commenced.