Aim: To examine associations between socio-economic, familial and perinatal factors with overweight/obesity in 6- and 12-year-old schoolchildren.
Methods: Eligible year-1 (1765/2238, mean age 6.7 years) and year-7 students (2353/3144, mean age, 12.7 years) from a random cluster sample of 55 Sydney schools were examined during 2003–2005. Height, weight and body mass index were measured. Overweight or obesity was classified using International Obesity Task Force cut points. Information about each child's socio-demographic status, familial and perinatal information was sought in parental questionnaires.
Results: After multivariate adjustment, lower parental education was significantly associated with prevalent overweight and obesity in 6-year-old children, odds ratio (OR) 1.52 (95% confidence interval (CI) 1.15–2.01) and OR 2.16 (CI 1.34–4.13), respectively. Smoking during pregnancy was associated with a higher likelihood of being obese among both 6- and 12-year-old children, OR 1.90 (CI 1.05–3.46) and OR 1.78 (CI 1.22–2.61). Population attributable risk estimates indicate that 14.9% and 10.1% of prevalent cases of obesity in 12-year-old children may be attributable to being: an only child or a heavy newborn, respectively.
Conclusions: We show interdependent relationships between socio-economic, familial and perinatal factors and childhood weight status. Improved understanding of these pathways may help in developing childhood obesity prevention strategies.