There has been interest in the antecedents and mental health impacts of eating and body image disturbances in adolescence. Less is known about longer-term mental health impacts into young adulthood, as longitudinal studies with data spanning this developmental period are rare. We capitalize on mental health data collected across adolescence and young adulthood from a population-based cohort study that has been following >2000 Australian children and their families from infancy to young adulthood.