How Ultra-Processed Foods Could Be Impacting Your Fertility

What you eat may directly influence your chances of conceiving. Diet high in ultra-processed foods could be quietly affecting fertility.

A large U.S. study from McMaster University has found that women who consume fewer ultra-processed foods have higher chances of conceiving.
Published in Nutrition and Health, the research analyzed over 2,500 women from NHANES data and showed that higher intake of processed foods is linked to reduced fertility—even after accounting for age, weight, lifestyle, and health factors (1^✔ ✔Trusted Source
Ultra-processed food intake and Mediterranean diet adherence in relation to fertility status in U.S. women: Findings from NHANES 2013–2018

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Infertility is a growing global concern. Around 1 in 6 people worldwide are affected, making it critical to identify modifiable lifestyle factors such as diet.

What Did the Study Reveal About Diet and Fertility?

The study examined data from over 2,500 women who took part in the National Health and Nutrition Examination Survey (NHANES), which uses interviews, 24-hour dietary recalls, and laboratory tests to provide detailed insights into diet, demographics, and overall health.

Findings showed that women experiencing infertility consumed higher amounts of ultra-processed foods, accounting for about 31 percent of their daily intake. They also showed lower adherence to the Mediterranean diet, pattern rich in fruits, vegetables, whole grains, and healthy fats.

Even after adjusting for factors such as age, weight, and lifestyle, higher intake of ultra-processed foods was linked to around 60 percent lower chances of conception, underscoring a strong connection between diet and reproductive health.

Why Could Processed Foods Affect Hormones?

The findings suggest that what we eat—and how it is processed—may influence reproductive health in a manner well beyond calories or weight.

“Most of what we hear about ultra-processed foods focuses on calories and obesity. But our findings suggest something potentially more complex – there seems to be another mechanism at play which may reflect pathways beyond calories or weight, including chemical exposures that have been hypothesized in prior literature,” explains Anthea Christoforou.

Ultra-processed foods are industrially manufactured products made with refined ingredients, additives, and preservatives designed to enhance taste, texture, and shelf life. Common examples include packaged snacks, sugary drinks, instant meals, and processed meats.

Unlike whole or minimally processed foods, they often contain artificial compounds and fewer essential nutrients. Scientific evidence indicates that these substances can interfere with ovarian function, ovulation, and overall hormone balance, affecting fertility outcomes.

Additionally, ultra-processed foods are associated with inflammation, lower nutrient quality, and changes in the gut microbiome—all of which may further influence reproductive health.

Is It Just Weight or Something More?

To gain deeper insight into overall diet quality, researchers also evaluated adherence to the Mediterranean diet—a nutrient-rich eating pattern centered on fruits, vegetables, whole grains, and healthy fats.

The Mediterranean diet showed a positive association with fertility. However, this benefit disappeared once obesity was taken into account, suggesting its effects may be partly linked to maintaining a healthy weight and metabolism (2^✔ ✔Trusted Source
1 in 6 people globally affected by infertility: WHO

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In contrast, the link between ultra-processed foods and lower fertility remained significant even after adjusting for obesity. This indicates that factors beyond body weight—such as hormone disruption and metabolic changes—may be driving the association.

Because this was a cross-sectional study, the findings show association rather than cause and effect. However, the consistency of results across multiple adjusted models strengthens the significance of the link.

“Very few studies have asked a fundamentally female-specific question: how does what women eat influence their reproductive health? Fertility is a huge outcome, and this is the first time anyone has examined these dietary patterns and infertility at this scale,” says Christoforou.

“It suggests diet may be an important and measurable factor associated with women’s ability to conceive. It’s one thing to say ultra-processed foods contribute to weight gain or cardiometabolic disease. But if they’re also affecting hormone pathways, that’s a much bigger issue — and it’s something people aren’t as aware of,” she says.

This latest study builds on previous research linking ultra-processed foods to poor health outcomes.

“Processing affects foods in ways that aren’t reflected in nutrients alone – from chemical exposures during manufacturing to ingredients that displace whole, protective foods,” says Baric.

“It’s not about perfection – it’s about noticing how food is processed, choosing more foods in their natural states and picking ingredients you recognize. Even that simple shift can lower exposure to things we still don’t fully understand.”

References:

1. Ultra-processed food intake and Mediterranean diet adherence in relation to fertility status in U.S. women: Findings from NHANES 2013–2018 – (https://journals.sagepub.com/doi/10.1177/02601060261433154)
2. 1 in 6 people globally affected by infertility: WHO – (https://www.who.int/news/item/04-04-2023-1-in-6-people-globally-affected-by-infertility/)

Source-Medindia