Childhood obesity trajectories and adolescent mental health: A UK cohort study

Background: We examined how obesity trajectories and time living with obesity during childhood predict mental health at age 17. Methods: Data were from the UK Millennium Cohort Study. Obesity trajectory groups between ages 7 and 17 (n=8,306) and previous obesity episodes from ages 7, 11, and 14 (n=7,246) were examined. Caregiver-reported internalising and externalising symptoms at age 17 were assessed. Linear regression models were used.Results: Obesity development and persistence (vs. never developing obesity) were associated with worse internalising symptoms at age 17, and worsening trajectory of these symptoms between age 7 and 17. Evidence of worse externalising symptoms at age 17 and a worsening trajectory of these symptoms over time only appeared for obesity development (vs. never developing obesity). Obesity reversal (vs. never developing obesity) by age 17 was not associated with worsening mental health. Having multiple episodes of obesity in the past was not associated with worsening mental health in individuals with and without current obesity at age 17.Conclusions: Development and persistence of obesity from ages 7-17 are associated with worsening mental health. If childhood obesity is reversed, there appears to be no evidence of a negative effect of previous obesity on mental health at age 17.