Engberg E, et al. - Via this prospective 3-year follow-up study, researchers determined if sedentary screen time alters when transitioning from childhood to adolescence and if body mass index (BMI) in adolescents is influenced by children's screen time, separately for school days and weekends. Participants were 5,084 children who had mean (standard deviation) ages of 11 (1) years and 14 (1) years at baseline and at follow-up, respectively. They inquired children for self-reported screen time, more precisely, time spent seeing TV programs and using a computer outside school while sitting. Separately for school days and weekends, the children were grouped as light, medium, and heavy TV viewers and computer users. The calculation of the age- and gender-specific BMI z-score was also done. Findings revealed a rise in the proportion of heavy screen users when transitioning from childhood to adolescence. A link was identified between heavy screen use, particularly on weekends in 11-year-old children and an increased BMI 3 years later.