According to research reviewed by Gram, women whose diets were most inflammatory had 54% higher odds of infertility than women whose diets were least inflammatory. The 2026 study of 2,236 U.S. women found the link was strongest in women with obesity, though it cannot prove that diet causes infertility.
A new study looked at how the food women eat may affect their ability to get pregnant. According to research reviewed by Gram, women whose diets scored highest for promoting inflammation, a body process linked to many health problems, had 54% higher odds of infertility than women with the lowest scores. The study used national health survey data from 2,236 U.S. women aged 18 to 45. The link was strongest in women with obesity. Because the study looked at a single point in time, it can show an association but cannot prove that diet causes infertility. Still, the findings suggest that everyday eating habits may matter for reproductive health, especially for women who already face weight-related health risks.
Key Statistics
A 2026 cross-sectional study of 2,236 U.S. women aged 18 to 45 found that women with the most inflammatory diets had 54% higher odds of infertility than women with the least inflammatory diets.
In the same study, the link between diet and infertility was strongest among women with obesity, where the predicted probability of infertility reached 30% at high levels of dietary inflammation.
The Quick Take
- What they studied: The researchers asked whether women who eat more inflammatory foods are more likely to have trouble getting pregnant, and whether body weight changes this relationship.
- Who participated: The study used data from 2,236 women aged 18 to 45 in the United States. The data came from a national health survey run between 2013 and 2018, so the women represent a broad cross-section of the U.S. population.
- Key finding: Women with the most inflammatory diets had 54% higher odds of infertility than women with the least inflammatory diets. The link was much stronger in women with obesity, where the estimated chance of infertility reached 30% at high levels of dietary inflammation.
- What it means for you: Eating a diet with more vegetables, fruits, whole grains, and fish and less processed food may support overall reproductive health. However, this study cannot prove that changing your diet will improve your fertility, so talk with a doctor if you are trying to conceive.
The Research Details
This was a cross-sectional study, which means the researchers collected information from many people at one point in time. They used data from the National Health and Nutrition Examination Survey, a large national study run by the U.S. government. The survey asked women to recall everything they ate and drank in the previous 24 hours.
The researchers used these food records to calculate a Dietary Inflammatory Index, or DII. This score rates how much a person’s overall diet may promote or reduce inflammation in the body. Foods such as refined grains, sugary drinks, and processed meats tend to push scores higher, while vegetables, fruits, and fish tend to lower them. The women were then divided into four groups based on their scores, from lowest to highest inflammation.
Infertility was based on what the women reported about themselves, such as whether they had trouble getting pregnant. The team used statistical tools to account for factors like age and other health traits, and they tested whether body mass index (BMI), a measure of body weight relative to height, changed the link between diet and infertility.
Looking at a whole diet, rather than a single food, gives a broader picture of how eating patterns relate to health. Because the survey covers many women across the country, the results may apply to a wide range of people, not just one clinic or small group. Testing whether BMI changes the link also helps identify who may be most affected.
The study used a large, nationally representative survey, which is a strength. It was published in a peer-reviewed journal, meaning other experts reviewed it before publication. The researchers used weighting and statistical controls to make the sample more representative and to account for other factors.
However, there are important limits. Both diet and infertility were measured by asking people to report on their own experiences, which can be inaccurate. A single 24-hour food recall may not reflect what someone usually eats. The design also cannot show which came first or prove cause and effect.
What the Results Show
The main result was that women with higher inflammatory diet scores were more likely to report infertility. Compared with women in the lowest group for inflammatory eating, women in the highest group had 54% higher odds of infertility. In statistical terms, the odds ratio was 1.54, with a 95% confidence interval of 1.02 to 2.32. This range suggests the true effect is likely to be somewhere between a small increase and a fairly large one. The trend across the four groups was statistically significant (P trend = .026), which means the risk generally rose as diet inflammation scores went up.
Body weight appeared to play a major role. The researchers found a strong interaction between diet and BMI (P interaction below .0001). This means the connection between diet and infertility was not the same for every woman. It was most pronounced in women with obesity, defined as a BMI of 30 kg/m2 or higher.
Among women with obesity, the predicted probability of infertility reached about 30% at the highest levels of dietary inflammation. This figure is a model estimate, not a count of women who actually experienced infertility in the study, so it should be read as an illustration of the pattern rather than an exact risk for any individual.
Taken together, the results suggest that diet quality and body weight may work together to influence fertility. The findings do not establish a direct cause, but they point to diet as a factor worth studying further.
The researchers also looked at how the results changed when they adjusted for other factors. The association remained in their main analyses, which suggests the link was not explained only by age or other basic traits. The stronger pattern in women with obesity is an important secondary finding, because it suggests that the same diet may carry different risks depending on body weight. This could help doctors and public health experts target support to women who may benefit most.
Previous research has linked chronic inflammation to a range of reproductive problems, including conditions that affect ovulation and egg quality. Studies on obesity have also found that excess body weight is associated with lower fertility. This study adds to that body of work by connecting the overall inflammatory quality of the diet to infertility in a large U.S. sample, and by showing that body weight appears to strengthen that connection.
The study cannot prove that inflammatory foods cause infertility. Many other factors, such as stress, sleep, smoking, medical conditions, and access to care, could also play a role, and not all of them may have been fully measured. Infertility was self-reported, so some women may have misremembered or defined it differently. Diet was measured with a single day of recall, which may not reflect typical eating habits. The Dietary Inflammatory Index is also a research tool based on the average effects of foods, so it may not capture every individual’s response. Finally, the study included only women of childbearing age in the United States, so results may not apply to other populations.
The Bottom Line
Based on this study, eating a diet lower in highly processed foods and higher in vegetables, fruits, whole grains, and fish may be a reasonable step for overall health, including reproductive health. Confidence in this recommendation is moderate, because the general benefits of these foods are well established, but this specific study only shows an association. Confidence that diet alone will improve fertility is low at this stage. Women who are trying to conceive should discuss their concerns with a healthcare provider.
Women of childbearing age who are trying to conceive, those with weight concerns, and anyone interested in how everyday eating habits affect long-term health may find these findings useful. Clinicians and researchers may also want to explore this link further. People who are not concerned about fertility can still benefit from eating a less inflammatory diet for general health. Men, women outside this age range, and those with known fertility diagnoses should rely on individualized medical advice rather than this study alone.
Diet changes generally take several weeks to months to show measurable effects on inflammation markers in the body. Fertility is influenced by many factors and its timeline varies widely between individuals. Because this study does not prove diet changes improve fertility, it is not possible to say how long it would take to see results. If fertility is a concern, a doctor can advise on appropriate testing and timing.
Frequently Asked Questions
Does an inflammatory diet affect fertility in women?
A 2026 study using national health survey data from 2,236 U.S. women found that a more inflammatory diet was linked to higher infertility risk. Women in the highest inflammation group had 54% higher odds of infertility than those in the lowest group. The study shows an association, not proof of cause.
What is the Dietary Inflammatory Index?
The Dietary Inflammatory Index is a score that estimates how much a person’s overall diet may promote or reduce inflammation in the body. It is calculated from food intake data, and higher scores reflect eating patterns linked to more inflammation, such as frequent processed and sugary foods.
Does body weight change how diet affects infertility risk?
Body weight appeared to matter a great deal in this study. The link between diet and infertility was strongest in women with obesity, defined as a BMI of 30 kg/m2 or higher. Statistical testing found this difference was very unlikely to be due to chance, with P below .0001.
Can changing my diet improve my chances of getting pregnant?
Current research has not shown that diet changes improve fertility. This study found only an association and relied on self-reported infertility and one-day food recalls. Eating more vegetables, fruits, whole grains, and fish supports general health, but anyone concerned about fertility should speak with a doctor.
Want to Apply This Research?
- Log your daily food intake for at least 7 days and track the number of servings of vegetables, fruits, whole grains, fish, and processed or sugary foods. Use the app to compare your weekly totals, aiming to gradually increase plant-based and fish servings while reducing processed and sugary items.
- Set one small, specific goal, such as adding one extra vegetable serving to lunch and dinner each day, or swapping sugary drinks for water or unsweetened tea. Use the app’s reminders to build the habit, and check your progress each week.
- Review your food log monthly to see trends rather than daily ups and downs. Pair food tracking with notes on weight, sleep, and stress so you can see broader patterns. Share your trends with a healthcare provider during regular visits, especially if you are planning a pregnancy.
This article summarizes a cross-sectional study that found an association between diet and infertility, which does not prove that diet causes infertility. The information is for general education only and is not medical advice. Talk with a doctor or fertility specialist before making changes to your diet or fertility plans.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.