Mediterranean Diet Adherence and Sleep Quality in Spanish Adults: Divergent Associations Between Subjective and Objective Measures

Abstract

Objective: We aimed to examine the association between adherence to the Mediterranean diet (MD) and sleep quality assessed using both subjective and objective methods in a general adult population. Design: This is a cross-sectional study. Adherence to the MD was evaluated using the Mediterranean Diet Adherence Screener, while sleep quality was assessed subjectively using the Pittsburgh Sleep Quality Index and objectively using wrist actigraphy over five consecutive days. Multivariable linear and logistic regression models were applied, adjusting for key sociodemographic and clinical confounders. Settings: We investigated a general adult population from Spain with a total of 500 Spanish adults aged 25–65 years. Results: Higher MEDAS scores were significantly associated with better subjective sleep quality. Each one-point increase in MD adherence was associated with lower PSQI scores, and participants with higher adherence had lower odds of poor sleep quality, although this association did not reach statistical significance. Cluster analysis identified a dietary pattern characterized by higher consumption of fruits, vegetables, fish and olive oil that was associated with better perceived sleep quality. No significant associations were observed between MD adherence and objective sleep parameters, including sleep efficiency, sleep fragmentation or wake after sleep onset. Conclusions: Greater adherence to the MD was associated with better perceived sleep quality but not with objectively measured sleep parameters. These findings suggest that dietary patterns may influence sleep perception rather than objective sleep characteristics and highlight the potential role of the MD as a modifiable factor related to sleep-related well-being.