The association between preschool dietary patterns and mental health outcomes over two years

Poor diet quality is associated with greater depressive symptoms among older youth and adults. Whether dietary patterns in early childhood are also associated with later mental health (MH) outcomes remains unclear, as prospective evidence is limited. This study examined the association between dietary patterns at age 3 and MH symptoms at age 5. Participants were 2,076 children (47.4% female) from the CHILD Birth Cohort Study. MH outcomes were assessed at age 5 using the Child Behaviour Checklist. Dietary patterns were assessed at age 3 and categorized into three groups: 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). Multivariate linear regression models examined the diet–Total Problems association. Internalizing and Externalizing Problems were examined in sensitivity analyses. Household income, sex, and maternal depression were explored as potential moderators. Greater adherence to a Prudent dietary pattern at age 3 was associated with fewer MH symptoms at age 5 (β = – 1.15, p < .001). Sensitivity analyses revealed similar associations for the internalizing (β = – 1.50, p < .001) and externalizing (β = – 0.72, p = .033) subscales. No significant moderation effects were observed. Western-like and Refined grain-Snack dietary patterns were not significantly associated with MH problems. A prudent dietary pattern may be an important modifiable protective factor for MH outcomes in early childhood. Findings support future research examining the effectiveness of early nutrition interventions in supporting child MH outcomes.