This study aimed to explore the associations of screen time (ST) and its' changes with follow-up body mass index (BMI) in preschool children. Parents of 805 preschoolers participated in our study at baseline and were followed up after 1 year in China. Linear regression models were used to analyze the dynamic relationship between ST and BMI in preschool children. A total of 662 preschoolers, including 342 boys (51.7%) and 320 girls (48.3%) were followed up. The changes in ST (from the initial ≤1 h/day to >1 h/day at follow-up vs keep ≤1 h/d, β(SE) = 0.21(0.09), P = .016) and follow-up ST of preschool children (>1 h/d vs ≤1 h/d, β(SE) = 0.17(0.07), P = .013) were significantly associated with an increase in the preschoolers' z-scored BMI at follow-up after adjusting for potential confounding factors. We concluded that the unfavorable change in ST was associated with increased BMI in preschool children.
Keywords: Screen-based sedentary behavior; child health; overweight; physical activity; prospective.