A large-scale study of 22,617 airline crew members found that irregular meal timing and eating patterns were associated with increased odds of anxiety and depression. Late dinners, eating windows longer than 12 hours, and meal jet lag were linked to poorer mental health outcomes.

Key findings from the study published in JAMA Network Open included:

• Late dinner (after 8 PM) on morning-shift days was associated with increased odds of anxiety (AOR: 1.78; 95% CI: 1.53-2.05) and depression (AOR: 2.01; 95% CI: 1.78-2.27).
• An eating window of less than 12 hours on morning-shift days was linked to reduced odds of anxiety (AOR: 0.84; 95% CI: 0.75-0.93) and depression (AOR: 0.81; 95% CI: 0.75-0.89).
• Delayed dinner on morning-shift days was associated with increased odds of anxiety (AOR: 1.32; 95% CI: 1.13-1.54) and depression (AOR: 1.39; 95% CI: 1.22-1.58).
• On morning-shift days, delayed eating rhythms were associated with higher odds of depression (AOR: 1.35; 95% CI: 1.13-1.61), while advanced eating rhythms were linked to lower odds of anxiety (AOR: 0.78; 95% CI: 0.70-0.87).

The study, conducted by researchers from Shanghai Jiao Tong University and collaborators, analyzed data from the Civil Aviation Health Cohort of China. Participants included pilots (34.9%), flight attendants (49.6%), and air security officers (15.5%) from ten Chinese airline companies, with a median age of 29.1 years.

Researchers examined meal timing on different shift days, daily eating windows, and meal "jet lag" - the difference in mealtimes between work and rest days. Mental health was assessed using the 7-item Generalized Anxiety Disorder Assessment and the 9-item Patient Health Questionnaire.

The study highlighted the potential impact of dietary rhythms on mental health in shift workers, particularly in the high-stress aviation industry. These findings may have implications for developing interventions and policies to mitigate the adverse effects of irregular work hours on mental health, noted the study.

Proposed mechanisms for these associations included disruption of gut microbiota circadian rhythms, alterations in insulin secretion pathways, and impacts on the gut-brain axis. The researchers suggested that time-restricted eating may also have neuroprotective effects.

The study adjusted for numerous confounding factors, including age, sex, educational level, marital status, BMI, occupation, income, total flight hours, shift ratios, sleep duration, social jet lag, physical activity, and substance use.

The researchers noted the cross-sectional design was a limitation of the study and that the results might underestimate the true impact of dietary rhythms on mental health in the general population, given the resilience training typical of airline personnel.

The authors declared having no competing interests.