Impact of time-restricted eating on reproductive hormones and androgen markers in adult females: A systematic review

Background Time-restricted eating (TRE) is a popular dietary intervention shown to facilitate weight loss. However, the impact of TRE on female reproductive hormones and androgen markers is not clear. Aim This systematic review aimed to synthesise and evaluate the current body of evidence on the effect of TRE on reproductive hormones and androgen markers in adult females. Methods A systematic search was conducted across PubMed, Embase, CINAHL and Web of Science. All randomised controlled trials, pre–post and pilot/feasibility studies until May 2024 meeting the predefined inclusion criteria were included. Two researchers screened and selected eligible studies and extracted relevant data. Eligible studies methodological quality was assessed using the American Dietetic Association (ADA) Quality Criteria Checklist. Results Six studies met the inclusion criteria. Randomised controlled trials (RCTs) conducted in women with general obesity (body mass index > 30 kg/m 2 ) consistently found no significant changes in androgens or other key hormones (testosterone, oestrogen, progesterone, luteinising hormone, cortisol, dehydroepiandrosterone and sex hormone-binding globulin). In contrast, non-randomised studies focusing on women with polycystic ovary syndrome (PCOS) reported beneficial changes to hormone profiles, including decreased testosterone and luteinising hormone, although these effects may have been confounded by weight loss. Conclusion While limited by six studies, the current evidence on TRE's impact on female hormones is inconclusive and varies significantly by population and study design. While TRE appears to be a hormonally safe weight-loss strategy in women with general obesity, more rigorous, long-term RCTs are needed to establish its therapeutic role, in particular for conditions like PCOS.