Exploring the associations of depressive symptoms with healthy eating self-efficacy over time amongst women in the READI cohort study

BACKGROUND: There is growing evidence that diet is associated with both depressive symptoms and clinical depression, likely through biological mechanisms. However, it is also plausible that depression impacts diet, for example by impairing the personal drivers of healthy eating behaviors such as self-efficacy. This study is one of the first to explore the association of depressive symptoms with healthy eating self-efficacy over time. METHODS: Data was drawn from the Resilience for Eating and Activity Despite Inequality (READI) longitudinal study, a prospective cohort study of socioeconomically disadvantaged Australian women. This analysis includes a sub-sample of 1264 women. Linear mixed models, with random intercepts for suburb of residence, were performed to explore the relationships between total healthy eating self-efficacy at 5-years follow-up and depressive symptoms over time, whilst adjusting for potential confounders. To assess different trajectories of depressive symptoms over time, four categories were created; 1. no depressive symptoms (n = 667), 2. resolved depressive symptoms (n = 165), 3. new depressive symptoms (n = 189), and 4. persistent depressive symptoms (n = 243). RESULTS: There was very strong evidence of a difference in total healthy eating self-efficacy at follow-up between the four depressive symptoms trajectory categories (F(3,235) = 7.06,p < .0001), after adjusting for potential confounders. Pairwise comparisons indicated strong evidence of higher healthy eating self-efficacy among individuals with no depressive symptoms compared to individuals with persistent depressive symptoms (B = 1.97[95%CI: 0.60,3.33],p = .005). Similarly, there was evidence of higher healthy eating self-efficacy in individuals with resolved depressive symptoms than those with persistent depressive symptoms (B = 1.95[95%CI: 0.18,3.72],p = .031). CONCLUSIONS: This study provides new insights demonstrating differences in total healthy eating self-efficacy at 5-year follow-up according to trajectory of depressive symptoms over time. Future interventions should focus on strategies that enhance self-efficacy among individuals with or at risk of depressive symptoms for supporting healthier dietary practices, which in turn, may contribute to reducing the highly burdensome mental health condition.