Children and adolescents spend considerable time online. The current study investigated moderators of short-term longitudinal associations from social media use to changes in body satisfaction and physical activity. Participants (144 girls, 152 boys) were third-sixth grade students (ages 8-13) attending public schools in Florida (USA).…

School-age children with overweight or obesity continue to be problematic in the United States, and are associated with many health, social, and financial problems. Schools provide an excellent venue in which to promote healthy weight in students, and school nurses are well-positioned to play an essential role in controlling obesity. The number of…

Background: Cluster-randomized experiments that assign intact groups such as schools or school districts to treatment conditions are increasingly common in educational research. Such experiments are inherently multilevel designs whose sensitivity (statistical power and precision of estimates) depends on the variance decomposition across levels.…