Feasibility study finds time-restricted eating safe in PCOS with exploratory metabolic signals

OBJECTIVE: Time-restricted eating (TRE) represents a novel intervention that may improve hyperinsulinaemia and reduce weight, but has not been studied in polycystic ovarian syndrome (PCOS). In a randomised interventional study (NCT05126199 [1]), we investigated the feasibility of TRE in PCOS including recruitment, compliance, safety, drop-out rate, and effect on insulin-related parameters, anthropometrics, nutritional intake and metabolic indices. METHODS: Participants were randomised to a 12-week TRE regimen (18 h fast/6 h eating window) or 'ad libitum' regimen (no time-restriction), and then crossed over to the alternative regimen for a further 12 weeks. RESULTS: TRE was a feasible intervention with near-total compliance in those completing the intervention; however, there were considerable difficulties with recruitment. A total of 70 were eligible to participate, of which ultimately 15 were recruited, and 11 completed the study (4 [27%] drop-outs due to commitment/study duration). There were no serious adverse events in the TRE group. Compliance [%(SD)] with TRE was 94.7(4.5)%, and 10 participants were keen to continue the intervention post-study. Whilst the study was not powered to detect changes in metabolic or anthropometric indices, exploratory analysis showed a decrease in HbA1c (p = 0.04), weight (p = 0.001), BMI (p = 0.001), hip circumference (p = 0.05) and waist circumference (p = 0.001) in the TRE group compared to the ad libitum eating group. CONCLUSION: In a 12-week cross-over feasibility study, TRE was a safe and feasible intervention. Recruitment was challenging and with limited numbers, the TRE group showed a decrease in HbA1c and anthropometric indices compared to the 'ad libitum' group. TRIAL REGISTRATION: NCT05126199.