Ultra-Processed Foods and Fertility: What the Data Shows

FertilityAll Evidence-Based Posts
Written By Rachel Goldberg

This study examined the relationship between diet and fertility in a nationally representative sample of U.S. women ages 20–45. The primary focus was on:

  • Ultra-processed food (UPF) intake

  • Mediterranean diet (MD) adherence

  • Self-reported infertility (defined as attempting to conceive for 12 months or longer)

Data were drawn from NHANES (2013–2018), including 2,582 participants. 

Key Findings

Women reporting infertility had:

  • Higher ultra-processed food intake (30.6% vs 26.7%)

  • Lower Mediterranean diet scores

  • Higher UPF intake was associated with lower odds of fertility

  • This association remained significant after adjusting for sociodemographic, lifestyle, and obesity-related factors

  • Mediterranean diet adherence was associated with higher odds of fertility in initial models

  • This association was no longer significant after adjusting for obesity 

Interpretation of Findings

Ultra-processed food intake showed a consistent inverse association with fertility across all models. Mediterranean diet adherence did not remain independently associated with fertility after accounting for obesity. This suggests the observed relationship may be explained by weight-related or metabolic factors rather than the dietary pattern itself.

Proposed Mechanisms

The study outlines several possible pathways linking ultra-processed food intake to reproductive outcomes:

  • Lower intake of nutrients relevant to reproductive health

  • Increased systemic inflammation

  • Exposure to endocrine-disrupting chemicals (e.g., phthalates, bisphenols)

  • Alterations in metabolic function

  • Changes in gut microbiota composition 

These mechanisms are theoretical and not directly tested in this study.

Limitations

  • Cross-sectional design

    • Causation cannot be determined

  • Fertility status was self-reported

  • Dietary intake was based on 24-hour recall

  • Potential misclassification of ultra-processed foods

Despite these limitations, associations remained consistent across adjusted models. 

Conclusion

Higher intake of ultra-processed foods was associated with lower odds of fertility in U.S. women of reproductive age. Mediterranean diet adherence was not independently associated with fertility after adjustment for obesity.

The findings suggest dietary processing level may be a relevant factor in reproductive health, independent of total caloric intake and body weight.

Curious to learn more? You can explore blog reflections on infertility or dive into more fertility research insights .

Rachel Goldberg
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