Associations between diet quality and mental health in socially disadvantaged New Zealand adolescents

BACKGROUND/OBJECTIVES: To examine the relationship between diet quality and mental health in an ethnically diverse adolescent population in New Zealand. SUBJECTS/METHODS: Cross-sectional, population-based study design. Data were available at baseline for 4249 students. Responses from self-reported dietary questionnaires were used to assess diet quality; healthy eating and unhealthy eating were assessed as two separate scales. Mental health was assessed by the emotional subscale of the PedsQL instrument. RESULTS: Eating a healthy diet was significantly associated with better emotional health (P < 0.001) and eating an unhealthy diet was significantly associated with greater emotional distress (P < 0.001), after controlling for age, ethnicity and gender. The healthy and unhealthy eating scales were independently related to mental health scores. CONCLUSIONS: These findings contribute to a growing body of literature that diet quality is associated with mental health in adolescents. Further research is warranted to determine whether improvements to the diets of adolescents can have meaningful improvements to mental well-being.