The Effect of Weight Loss and Weight Loss Interventions on Sex Hormones: An Umbrella Review of Systematic Reviews and Meta-Analyses

Abstract

Objective: This umbrella review aims to comprehensively evaluate the effects of weight loss and various weight loss interventions, like bariatric surgery, dietary modifications, and physical activity, on sex hormone profiles in adults. The goal is to synthesize existing systematic reviews and meta-analyses to clarify the impact of different weight loss strategies on sex hormones.

Methods: A systematic search was conducted using Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines in PubMed, Scopus, Web of Science, and Embase for articles published up to and including April 2025. Three independent reviewers then screened and selected the studies to be included in the review, resolving discrepancies via consensus. Data extraction was performed to uncover study characteristics, intervention types, and hormone outcomes.

Results: Our analysis showed that bariatric surgery produced the most pronounced and consistent improvements in sex hormone profiles. In men, bariatric surgery significantly increases total testosterone (up to 8.73 nmol/L) and sex hormone-binding globulin (SHBG) (up to 21.22 nmol/L), with moderate- to high-quality evidence, and the strongest support is for improvements in luteinizing hormone, follicle-stimulating hormone, and SHBG following bariatric surgery. Dietary interventions also improved testosterone and SHBG, but to a lesser extent (QUANTIFY). In women, physical activity interventions modestly reduced total and free estradiol and increased SHBG.

Conclusion: Weight loss interventions significantly improve sex hormone profiles in adults with obesity, contributing to enhanced reproductive and sexual health outcomes. The quality of evidence varies by intervention and outcome. Still, our analysis suggests bariatric surgery has the highest benefit, independent of and out of proportion to the amount of actual weight loss.

Keywords: bariatric surgery; meta-analyses; sex hormones; systematic reviews; weight loss.