New research suggests diet quality not just calories could play a role
April 28, 2026
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Recent research found that higher intake of ultra-processed foods was associated with lower odds of fertility in U.S. women.
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The link remained even after accounting for factors like age, weight, and lifestyle.
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Women experiencing infertility tended to consume more ultra-processed foods and follow less healthy dietary patterns.
If youve ever wondered whether what you eat could affect your chances of getting pregnant, new research suggests the answer might be yes especially when it comes to ultra-processed foods. These are the packaged, ready-to-eat items that make up a big part of many modern diets, from snack foods to frozen meals.
A recent study from researchers at McMaster University found that women who ate fewer ultra-processed foods had a higher likelihood of conceiving. Importantly, this connection held up even after researchers accounted for other factors that are typically linked to fertility, like age, body weight, and lifestyle habits.
The findings dont prove that ultra-processed foods directly cause infertility. But they do point to a meaningful relationship between diet quality and reproductive health one that goes beyond the usual focus on calories or weight alone.
Most of what we hear about ultra-processed foods focuses on calories and obesity, researcher Anthea Christoforou said in a news release.
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.
How the study worked
To explore this link, researchers analyzed data from U.S. women collected through the National Health and Nutrition Examination Survey (NHANES) between 2013 and 2018.
They looked at participants dietary habits specifically how much of their daily food intake came from ultra-processed foods alongside self-reported fertility status. Ultra-processed foods were identified using a standard classification system that groups foods based on how heavily theyre industrially processed.
The researchers also considered how closely participants followed a Mediterranean-style diet, which emphasizes whole foods like fruits, vegetables, whole grains, and healthy fats.
To make the results more reliable, the analysis adjusted for a range of variables that could influence fertility, including obesity and other lifestyle factors. This helped isolate the potential role of ultra-processed foods themselves, rather than other overlapping health behaviors.
What the researchers found
The results showed a clear pattern: women who reported infertility tended to consume more ultra-processed foods than those who did not. In fact, ultra-processed foods made up about 31% of daily intake among women with infertility, compared to lower levels among those who were fertile.
Overall, higher consumption of these foods was linked to significantly lower odds of fertility even after accounting for other health and lifestyle factors.
Researchers also noted that women experiencing infertility generally had lower adherence to healthier eating patterns, like the Mediterranean diet.
While the study doesnt establish cause and effect, it suggests there may be something about ultra-processed foods beyond just their calorie content that could influence reproductive health. That could include factors like additives or the way these foods are manufactured, though more research is needed to fully understand the mechanisms.
For now, the takeaway is fairly straightforward: diet quality may be one piece of the fertility puzzle, and the degree of food processing could matter more than many people realize.
Processing affects foods in ways that arent reflected in nutrients alone from chemical exposures during manufacturing to ingredients that displace whole, protective foods, researcher Angelina Baric said.
Its not about perfection its 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 dont fully understand.