“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.