Depressive symptoms among single-person households: roles of dietary habits and frequency of eating meals with others.

The global prevalence of single-person households is rapidly increasing. However, emerging evidence indicates that individuals living alone are at greater risk of experiencing depressive symptoms. Therefore, this study aims to investigate the mediating roles of dietary quality and eating companionship in the relationship between household type and depressive symptoms. Data from the 2016, 2018, and 2020 Korean National Health and Nutrition Examination Survey were analyzed, comprising 13,357 participants aged ≥20 years. Depressive symptoms were measured using the Patient Health Questionnaire-9 (PHQ-9), dietary quality with the Korean Healthy Eating Index, and eating companionship through the frequency of eating alone. Logistic regression and causal mediation analyses were performed, adjusting for demographic and socioeconomic variables. Sampling weights were applied to ensure national representativeness. Individuals in single-person households exhibited significantly higher odds of experiencing mild-to-severe (PHQ-9 ≥5) and moderate-to-severe (PHQ-9 ≥10) depressive symptoms compared with those in multi-person households across all age groups. Lower dietary quality and a higher frequency of eating alone were significantly associated with increased depressive symptoms. Causal mediation analysis indicated that dietary quality accounted for 8.4 % and 10.7 % of the associations with mild-to-severe and moderate-to-severe depressive symptoms, respectively, while the frequency of eating alone mediated 30.3 % and 38.5 % of these associations. Poor dietary quality and frequent solitary eating mediate the association between living alone and depressive symptoms. Public health interventions that encourage healthier eating habits and promote shared mealtimes may help alleviate depressive symptoms among the increasing population of individuals living alone.