Increasing prevalence of obesity in South Australian 4-year-olds: 1995-2002

Objective: To determine prevalence of, and trends in, overweight and obesity in South Australian children aged 4 years during the period 1995-2002. Methods: Data from 114 669 children collected as part of Child and Youth Health 'preschool health assessments' of 4-year-olds throughout the state in the years 1995-2002 were analysed. Body mass index was calculated from height and weight data and prevalence of overweight and obesity for males and females determined using a standard world-wide definition. Yearly prevalence rates were compared for changes over time. Results: Rates of overweight and obesity have increased over the period 1995-2002. In 1995, of females 12.8% were overweight or obese (obese 3.5%). Of males 10.2% were overweight or obese (obese 3.2%). The equivalent figures in 2002 were for females 21.4% (obese 5.8%) and males 17.3% (obese 4.1%). Rates of overweight and obesity were greater in females than males in all years (except obesity rate in 1995). Conclusion: Data from this large, consecutive yearly dataset of South Australian 4-year-old children show a significant increase in the rates of overweight and obesity. Much of this increase appears to have occurred in the mid-to-late 1990s. It is uncertain if these changes have plateaued at this time. These results reinforce rising obesity prevalence as a significant child health issue. They also indicate that obesity is seen as early as the preschool years; with implications for theories of causation and for prevention and treatment strategies.