Association Between Mediterranean Diet Adherence and Sleep Quality: A Sex-Specific Analysis From the Korean Genome and Epidemiology Study

Objective: This study aimed to examine the relationship between adherence to the Mediterranean diet (MD) and sleep quality in a Korean population. Methods: We analyzed data from 7,861 participants aged 40–69 years in the Korean Genome and Epidemiology Study cohort. MD adherence was measured using the Korean version of the Mediterranean Diet Adherence Screener, and sleep duration and poor sleep quality indicators were evaluated. Dietary intake was assessed using a 103-item food frequency questionnaire. After propensity score matching, the analysis included 1,485 men and 2,676 women. Sex-stratified logistic regression models were conducted, adjusting for age, education, body mass index, physical activity, smoking, alcohol consumption, energy intake, household income, employment status, marital status, residential area, and chronic diseases. Results: No significant association was observed between MD adherence and poor sleep quality in men. In women, higher adherence to the MD was associated with lower odds of reporting multiple poor sleep quality indicators, with an odds ratio (OR) of 0.82 (95% confidence interval [CI]: 0.69–0.97, p=0.024) for 2–3 indicators and 0.83 (95% CI: 0.72–0.97, p=0.018) for ≥4 indicators. Additionally, higher adherence was significantly associated with reduced odds of not feeling rested in the morning (OR: 0.80, 95% CI: 0.66–0.97, p=0.024), suggesting a sex-specific effect of the MD on sleep quality. Conclusion: MD adherence did not affect sleep quality in men but was associated with better sleep quality in women, particularly by reducing morning fatigue. Therefore, promoting MD may be critical in improving sleep and reducing health risks in women.