Objective: TV viewing and computer use is associated with childhood overweight, but it remains unclear as to how these behaviours could best be targeted. The aim of this study was to determine to what extent the association between TV viewing, computer use and overweight is explained by other determinants of overweight, to find determinants of TV viewing and computer use in the home environment and to investigate competing activities.
Method: A cross-sectional study was carried out among 4072 children aged 4-13 years in the city of Zwolle, the Netherlands. Data collection consisted of measured height, weight and waist circumference, and a parental questionnaire on socio-demographic characteristics, child's nutrition, physical activity (PA) and sedentary behaviour. Associations were studied with logistic regression analyses, for older and younger children, boys and girls separately.
Results: The odds ratio (OR) of being overweight was 1.70 (95% confidence interval (CI): 1.07-2.72) for viewing TV >1.5 h among 4- to 8-year-old children adjusted for all potential confounders. Computer use was not significantly associated with overweight. Determinants of TV viewing were as follows: having >2 TVs in the household (OR: 2.38; 95% CI: 1.66-3.41), a TV in the child's bedroom and not having rules on TV viewing. TV viewing and computer use were both associated with shorter sleep duration and not with less PA.
Conclusion: Association between TV viewing and overweight is not explained by socio-demographic variables, drinking sugared drinks and eating snacks. Factors in the home environment influence children's TV viewing. Parents have a central role as they determine the number of TVs, rules and also their children's bedtime. Therefore, interventions to reduce screen time should support parents in making home environmental changes, especially when the children are young.