Mediterranean Diet Adherence and Sleep Quality Among Primary and Secondary School Teachers in Portugal: An Exploratory Cross-Sectional Study.

Background: Diet and sleep are modifiable lifestyle factors that influence health and well-being. While adherence to the Mediterranean diet has been associated with improved sleep quality, this relationship remains understudied in high-stress occupational groups such as school teachers.

Objective: To examine the association between adherence to the Mediterranean diet and self-reported sleep quality among primary and secondary school teachers in Portugal.

Methods: A cross-sectional study was conducted with 113 teachers who completed a self-administered digital questionnaire. Adherence to the Mediterranean diet was assessed using the 14-item Mediterranean Diet Adherence Screener (MEDAS) and sleep quality was evaluated with the Pittsburgh Sleep Quality Index (PSQI).

Results: Of the 113 participants, 58% reported poor sleep quality (PSQI > 5), and the median PSQI score was 6.0 (IQR 4.0-8.8). The median MEDAS score was 9.0 (IQR 8.0-10.0), with 34% classified as having high adherence. When stratified by dietary adherence, there were no statistically significant differences in global PSQI or its components, and multivariable linear regression showed no association between MEDAS and PSQI. Patterns varied by teaching level: poor sleep predominated in most levels except the 2nd Cycle; high adherence was most prevalent in the 1st Cycle, moderate adherence predominated in the 3rd Cycle and secondary education, and the 2nd Cycle showed similar shares of moderate and high adherence.

Conclusions: In this occupational group, poor sleep was common and varied across teaching levels, while Mediterranean diet adherence showed no detectable association with overall sleep quality in this study. Larger, longitudinal studies using objective assessments of diet and sleep, and accounting for factors such as stress and chronotype, are warranted to clarify potential links in educational settings.