Association between proinflammatory diet and infertility among US reproductive-aged women: A cross-sectional study from NHANES 2013–2018

This study aimed to examine the association between the Dietary Inflammatory Index (DII) and infertility among United States women of childbearing age and assess whether body mass index (BMI) modifies this relationship. A cross-sectional analysis of National Health and Nutrition Examination Survey (2013-2018) included 2236 women aged 18 to 45 years. DII was derived from 24-hour dietary recall, and infertility was self-reported. Weighted logistic regression and interaction analyses were used. Higher DII scores were associated with increased infertility risk. Compared to the lowest DII quartile, the highest quartile had 54% higher odds of infertility (odds ratio = 1.54; 95% confidence interval: 1.02-2.32; P trend = .026). BMI significantly modified the association (P interaction < .0001). The strongest effect was observed in obese women (BMI ≥ 30 kg/m2), with predicted infertility probability reaching 30% at high DII levels. Proinflammatory diets are associated with higher infertility risk, particularly among obese women. Reducing dietary inflammation may be a promising strategy for infertility prevention in vulnerable populations.