“Goldilocks Days” for Adolescent Mental Health: Movement Behaviour Combinations for Well-Being, Anxiety and Depression by Gender

•Movement behaviours consisted of sleep, physical activity, and screen time.•Mental health measures included flourishing, resiliency, anxiety and depression.•Best day scenarios maximized sleep and physical activity while minimizing screen.•For transgender youth small difference in activity associated better mental health.•Screen use associated with less severe poor mental health in boys.