Associations between body mass index and sleep duration in Brazilian children and adolescents: the moderating role of screen time.

Abstract

Objectives: To verify the moderating role of screen time in the relationship between body mass index (BMI) and sleep duration in children and adolescents.

Methods: This cross-sectional study involved 1,338 children and adolescents (aged 6-17 years old; 761 girls) recruited from a municipality in south Brazil. Body weight and height were assessed to calculate BMI. Information regarding screen time, sleep duration, age, sex, sexual maturation, housing area, and socioeconomic status was obtained through a self-reported questionnaire. Moderation was tested using multiple linear regression modelling through an SPSS program extension. All models were adjusted for sex, age, sexual maturation, housing area, and socioeconomic status.

Results: No association was found between BMI and sleep duration (β=0.830; 95 % CI=-0.943; 2.603). However, when the role of screen time was considered, it was observed that this variable significantly moderated the relationship between BMI and sleep duration (β=-0.006; 95 % CI=-0.011; -0.001). Specifically, children and adolescents who spent more than 360 min per day in front of the screens presented higher BMI and shorter sleep durations.

Conclusions: The more time children and adolescents spend in front of screens, the higher the likelihood it will negatively affect their BMI and sleep duration. These findings emphasize the need for interventions that promote healthy screen habits and encourage behaviors that support optimal sleep duration to mitigate the potential negative effects on body weight and overall health.