Meal Timing Jetlag is associated with anxiety, depressive and insomnia symptoms in a French-speaking online cohort: A cross-sectional analysis of ALIMENTAL 2

BACKGROUND: Chrono-nutrition - when, not only what, one eats relative to circadian timing - is an emerging determinant of mental health. We tested whether Meal Timing Jetlag (MTJL), the workday-to-free-day discordance in eating schedules, is associated with anxiety (primary outcome) and with depressive and insomnia symptoms (secondary), independently of sleep-based circadian misalignment. METHODS: Cross-sectional analysis of the ALIMENTAL 2 French-speaking online cohort (n = 2945). Sleep timing was assessed with the Munich Chronotype Questionnaire and meal timing with a Food Timing Screener. Outcomes were the GAD-7 (anxiety), CES-D (depression) and ISI (insomnia). Multivariable models adjusted for age, sex, BMI, unemployment, financial difficulty and shift work, with dose-response, logistic and BMI-stratified sensitivity analyses. RESULTS: In the primary model (n = 2817), MTJL was independently associated with anxiety (β = +0.47/h, 95% CI [0.14, 0.79], p = 0.005). The relationship was J-shaped (non-linearity p = 0.020; slope above 1 h + 1.03/h, p < 0.001). MTJL was also associated with depressive symptoms (β = +1.81, 95% CI [1.00, 2.61], p < 0.001) and insomnia severity (β = +0.90, 95% CI [0.47, 1.33], p < 0.001). Sleep-based circadian phase and sleep social jetlag were not. The per-hour anxiety effect is modest (≈12% of the GAD-7 minimal clinically important difference). LIMITATIONS: The cross-sectional design cannot establish causality; reverse causation cannot be excluded. The cohort was online and 80% female, limiting generalisability. CONCLUSIONS: Meal-timing regularity may be a candidate behavioural correlate of anxiety, depression and insomnia, warranting longitudinal and interventional confirmation before any clinical recommendation.