Association between overweight or obesity and household income and parental body mass index in Australian youth: analysis of the Australian National Nutrition Survey, 1995

This study is a secondary data analysis based on the 1995 Australian National Nutrition Survey (NNS). A random subsample of 1581 school children aged 7-15 years old from the NNS was studied. The results show the prevalence of overweight, obesity and combined overweight and obesity was 10.6-20.9%, 3.7-7.2% and 15.6-25.7%, respectively. The odds ratio of overweight or obese boys with highest household income was significantly smaller than those with the lowest household income. The proportion of combined overweight and obesity in children whose parents were overweight or obese was significantly greater compared with those whose parents were not. The trend of increasing prevalence of overweight or obesity among children with increasing parental body mass index (BMI) was significant after adjusting for age except the trend of father's BMI for boys. This study provided baseline data on the recent prevalence of overweight or obesity of Australian school children using new international absolute BMI cut-off points. It indicated that young school girls (7-9 years) were more likely to be overweight or obese compared with boys, the prevalence rates of overweight or obesity in older boys (13-15 year) was significantly greater than in other age groups while in girls it was the opposite. The boys with lowest household income ($0-17 500) were more likely to be overweight or obese compared with those with the highest household income (greater than $67 500). Having parents especially mothers who were overweight or obese may increase the risk of children being overweight or obese.