OBJECTIVE: To determine the earliest developmental stage at which the association between unhealthy dietary patterns and depressive symptoms emerges, given that this relationship is well-documented in adolescents and adults but remains understudied in young children.
METHODS: Children (N = 2360; mean age of 5.1[SD = 0.2] years; 48% female) enrolled in the CHILD birth cohort study were included. Parent-reported data on demographics, dietary intake, sleep, physical activity, mental health outcomes (Child Behavior Checklist [CBCL]), and family variables (parental education, household income, maternal depressive symptoms) were collected. Missing covariate data with <15% missingness were handled using multiple imputations by chained equations. Dietary patterns were derived using Principal Component Analysis with a varimax rotation to enhance interpretability. Multiple regression was used to test the association between dietary patterns and mental health outcomes while accounting for covariates.
RESULTS: Three dietary patterns were identified: "Prudent" (high in vegetables, fruits, legumes, eggs, and fish); "Western-like" (high in fast foods, meats, and sugar-sweetened beverages); and "Refined Grain-Snack" (high in refined grains, dairy, and salty snacks). For the full sample, the mean CBCL subscale scores were as follows: Total Problems = 41.37[9.22], Internalizing Problems = 44.69[9.18], and Externalizing Problems = 39.78[9.65]. Greater adherence to the prudent pattern was associated with fewer Total Problems (β = -0.10, p = 0.003), Internalizing Problems (β = -0.10, p = 0.001), and Externalizing Problems (β = -0.08, p = 0.016 in fully adjusted models.
CONCLUSION: Findings suggest that the relationship between mental health and diet is observable in young children, highlighting a potential opportunity for preventive interventions. Longitudinal research is needed to determine the temporal association between dietary patterns and mental health symptoms.