Objectives: This study aimed to examine how physical activity (PA) and television (TV) viewing time of children varied according to family structure.
Methods: In 2001, 5- to 6-yr-old (N = 296) and 10- to 12-yr-old (N = 919) children and their parents were recruited from 19 state elementary schools in Melbourne, Australia. Children's PA was objectively assessed using accelerometers worn for 8 d. Sociodemographic and family structure information and time spent watching TV was collected via questionnaire completed by parents.
Results: ANCOVA revealed that, after controlling for socioeconomic status and age of child, boys without any siblings spent more minutes per day watching TV (153.2 ± 71.3) compared with those who have siblings (129.0 ± 64.4, P < 0.05). There were also significant differences in TV viewing time between boys with one sibling (125.5 ± 59.9), two siblings (141.9 ± 70.1), or three or more siblings (111.6 ± 62.6, P < 0.001). Girls from single-parent families (145.7 ± 85.1) spent significantly more minutes per day watching TV compared with girls from two-parent families (125.1 ± 67.7, P < 0.05). Girls with siblings spent more minutes per day in PA (148.3 ± 67.7) compared with those who were an only child (131.0 ± 58.9, P < 0.05). There were significant interactions between parental status and having a sibling, with PA, and also with TV viewing for girls and between parental status and having a brother with PA for boys. There were also significant interactions between having an older sibling and child's sex with PA and between number of siblings and sex with TV viewing.
Conclusions: Family structure may be an important source of influence on children's PA and TV viewing time. Aspects of family structure interact differently with PA and TV viewing, suggesting interventions may need to be tailored with consideration of the family structure of children.