The transition from elementary to secondary school is a challenging time for children as many obesity-related behaviors tend to worsen in this period. My research will examine how the familial environment can support a healthy transition; specifically, how parenting practices influence children’s choices with respect to diet, physical activity and sedentary time. I will first synthesize the published literature about how mothers’ and fathers’ parenting practices relate to children’s obesity-related behaviors. To gather real-world data, I will then use a combination of interviews, surveys, and wearable tech (accelerometers) with 150 British Columbian families to assess their parenting practices and children’s obesity-related behaviors daily for 14 consecutive days during elementary school, and again in secondary school. These data will be analyzed to identify how variations in parenting practices affect children’s behaviors day-to-day before and after the school transition, and the interviews will help understand more deeply how familial factors influence children’s behaviors. Together, my findings will guide the development of parenting interventions to help children maintain healthy behaviors during adolescence.