Irregular meal frequency and depressive symptoms: Moderating roles of dietary diversity and breakfast skipping

Irregular main-meal consumption frequency may disrupt metabolic and behavioral regulation, factors increasingly linked to affective disorders. However, evidence from nationally representative populations is limited.

We analyzed data from 21,568 adults in the 2014-2022 Korea National Health and Nutrition Examination Survey. Depressive symptoms were assessed with the PHQ-9. Multivariable logistic regression and restricted cubic spline analyses were conducted, adjusting for sociodemographic, lifestyle, and nutritional factors. Moderation and subgroup analyses examined dietary diversity, breakfast skipping, and lifestyle variables.

Irregular main-meal consumption frequency was associated with higher odds of depressive symptoms (adjusted OR for highest vs. lowest irregularity = 1.55, 95% CI 1.42-1.69, p < 0.001). The association was strongest in those with the lowest dietary diversity, while greater variety buffered adverse effects. Frequent breakfast skipping heightened susceptibility. No higher-order interactions were observed. Subgroup analyses showed stronger associations in men, smokers, and late-night eaters, though these require cautious interpretation.

Cross-sectional design, self-reported diet, and unmeasured confounders (stress, medication, sleep) may limit causal inference.

Irregular main-meal consumption frequency was associated with depressive symptoms, moderated by dietary diversity and breakfast habits, highlighting meal pattern regularity as a modifiable nutritional target for prevention.