National NHANES Study Finds 10 Percent Increase in Ultra-Processed Food Intake Linked to Significantly Lower Fertility Odds

New NHANES study finds every 10% increase in ultra-processed food intake significantly lowers fertility odds, while Mediterranean diet benefits vary by weight.

By: AXL Media

Published: Mar 23, 2026, 6:05 AM EDT

Source: Information for this report was sourced from Nutrition and Health

The Growing Reproductive Toll of Industrial Food Processing

As global infertility rates continue to impact millions, a new national study has identified a specific dietary culprit that may be sabotaging reproductive health in the United States. Analyzing data from the National Health and Nutrition Examination Survey, researchers found that women who struggled to conceive consumed a significantly higher proportion of ultra-processed foods compared to their fertile counterparts. Unlike general caloric intake, the level of food processing appears to exert a unique physiological strain on the female reproductive system, suggesting that what is in the food—and what was done to it—may be just as critical as the number of calories consumed.

Quantifying the Impact of Processed Diets on Conception

The study analyzed 2,582 women, finding that ultra-processed foods accounted for an average of 27% of daily caloric intake across the population. However, among those reporting infertility, that figure rose to 31%. The most striking finding was a linear correlation: for every 10% increase in the proportion of ultra-processed foods in a woman's diet, there was a statistically significant decrease in the odds of being classified as fertile. This association remained robust even after adjusting for factors such as age, smoking, and physical activity, marking processing level as a primary variable in reproductive outcomes.

The Complex Intersection of Mediterranean Diet and Obesity

While the Mediterranean diet is often hailed as a "gold standard" for anti-inflammatory health, its direct impact on fertility in this study proved more complex. Initial models showed that high adherence to Mediterranean-style eating—rich in fruits, legumes, and healthy fats—was linked to higher fertility odds. However, this benefit largely disappeared once researchers accounted for obesity. This indicates that while the Mediterranean diet supports fertility, its primary mechanism of action in this U.S. cohort may be its ability to help maintain a healthy body weight, which in turn supports hormonal balance.