Effects of time-restricted eating on body composition and metabolic parameters in overweight and obese women: a systematic review and meta-analysis

BACKGROUND: Time-restricted eating (TRE), a subtype of intermittent fasting, is increasingly explored as a dietary strategy for weight and metabolic management. However, its effects in overweight and obese women remain unclear. This systematic review and meta-analysis aimed to evaluate the impact of TRE on body composition and metabolic parameters in this population. METHODS: Following PRISMA guidelines and PROSPERO registration (CRD42024595472), randomized controlled trials were retrieved from eight English and Chinese databases up to August 2024. Eligible studies included adult women (≥85% female, BMI ≥ 25 kg/m²) receiving TRE interventions with or without caloric restriction. Quality was assessed using RoB 2.0 and the PEDro scale. Meta-analyses were conducted using Stata 17.0, with evidence certainty graded using GRADE. RESULTS: Thirteen RCTs involving 612 participants were included. TRE significantly reduced body weight (WMD = -1.927 kg, 95% CI: -3.688 to -0.166, p = 0.032) and fasting insulin levels (WMD = -2.120 μU/mL, 95% CI: -4.172 to -0.069, p = 0.043), but showed no significant effects on BMI, fat mass, fat-free mass, visceral fat, blood lipids, glucose, HOMA-IR, or blood pressure (p > 0.05). Subgroup analysis revealed greater weight reduction with TRE compared to conventional diets (p = 0.046), but not versus calorie restriction alone (p = 0.295). No lean mass loss was observed. Four studies reported minor adverse events (e.g., hunger, headache), all self-resolving. CONCLUSION: TRE is effective in reducing body weight and lowering fasting insulin in overweight and obese women, without negatively affecting lean body mass. Compared with traditional calorie-restricted diets, TRE does not yield superior weight loss, suggesting comparable efficacy. TRE demonstrates a favorable safety profile and better adherence, supporting its clinical feasibility. Further trials with larger samples and longer follow-up are needed to clarify TRE's long-term metabolic effects. SYSTEMATIC REVIEW REGISTRATION: The systematic review was registered in PROSPERO. Registration ID: CRD42024595472 URL: https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=459547.