Ultra-processed food consumption and risk of infertility in adults: a systematic review and meta-analysis
Background Ultra-processed foods (UPFs) have been linked to multiple adverse health outcomes; however, their association with infertility remains unclear. We conducted a systematic review and meta-analysis to evaluate the relationship between UPF consumption and infertility risk in adults. Methods PubMed, Web of Science, and Scopus were searched from inception to May 31, 2026. Eligible studies assessed UPF intake using validated dietary assessment tools based on the NOVA classification and reported infertility outcomes among adults aged ≥18 years. Two reviewers independently conducted study selection, data extraction, and risk of bias assessment using the Newcastle–Ottawa Scale and the Joanna Briggs Institute checklist. Pooled relative risks (RRs) with 95% confidence intervals (CIs) were estimated using random-effects models. Heterogeneity was assessed using the I2 statistic. Results Four studies providing five independent effect estimates and including 8,769 participants (8,118 women and 651 men) were included. In the random-effects model, higher UPF consumption was not significantly associated with infertility risk (RR = 1.26, 95% CI: 0.94–1.69), although the point estimate suggested a positive direction of association. Substantial between-study heterogeneity was present (I2 = 72.0%, p = 0.006). In sex-stratified analyses, no significant association was observed among women (RR = 1.26, 95% CI: 0.79–2.00; I2 = 68.4%). Subgroup analyses by study design and exposure assessment yielded no statistically significant associations under random-effects models. Conclusion Current evidence does not show a statistically robust association between UPF consumption and infertility under random-effects models, although estimates consistently suggest a positive trend. Evidence remains limited by few studies, substantial heterogeneity, and self-reported outcomes. Larger prospective, sex-specific studies are needed.