Diet quality and mental health in subsequent years among Canadian youth.

OBJECTIVE To examine the association between diet quality and the diagnosis of an internalizing disorder in children and adolescents. DESIGN A prospective study examining the relationship between diet quality and mental health. FFQ responses of 3757 children were used to calculate a composite score for diet quality and its four components: variety, adequacy, moderation and balance. Physicians' diagnoses on internalizing disorders were obtained by linking the children's dietary information to administrative health data. Negative binomial regression models were used to examine the association between diet quality and diagnosis of an internalizing disorder. SETTING The Canadian province of Nova Scotia. SUBJECTS A provincially representative sample of grade 5 students (age 10-11 years). RESULTS Diet quality was not found to be associated with internalizing disorder in a statistically significant manner (incidence rate ratio = 1.09; 95 % CI 0.73, 1.63). However, relative to children with little variety in their diets, children with greater variety in their diet had statistically significant lower rates of internalizing disorder in subsequent years (incidence rate ratio = 0.45; 95 % CI 0.25, 0.82). CONCLUSIONS These findings suggest the importance of variety in children's diet and opportunities in the prevention of adolescent depression and anxiety.