Sleep and the Mediterranean diet: A systematic review and meta-analysis

We conducted the current systematic review and meta-analysis to critically review and synthesize available evidence regarding the association between sleep duration, sleep quality, and chronotype with the Mediterranean diet (MedDiet) among the general population using observational studies. Online databases, including PubMed, Scopus, and ISI Web of Science, were searched from the earliest available date until December 2024. We enrolled 62 studies with a total sample size of 328,493. The mean age and BMI of the participants in the enrolled studies ranged from 6.1 to 74.7 years and 18.1-32.1 kg/m². Individuals with sufficient sleep duration (OR: 1.39; 95 % CI, 1.04, 1.85; P = 0.030; I² = 97.89 %, P_Q-test < 0.001), good-quality sleep (OR: 1.38; 95 % CI, 1.10, 1.73; P < 0.001; I² = 93.83 %, P_Q-test < 0.001), and earlier chronotype (OR: 1.74; 95 % CI, 1.21, 2.50; P = 0.002; I² = 89.72 %, P_Q-test < 0.001) had significantly increased odds of high MedDiet scores, compared to those with insufficient sleep duration, poor-quality sleep, and later chronotype, respectively. Our study revealed that sleep duration, sleep quality, and chronotype are lifestyle-related factors linked to MedDiet. However, more longitudinal studies and clinical trials are needed to investigate causality, mediating factors, and underlying mechanisms.