Prevalence of overweight and obesity in Australian children and adolescents: reassessment of 1985 and 1995 data against new standard international definitions

Objective: To review the prevalence of overweight and obesity in Australian children and adolescents in two national samples, 10 years apart, using th e new standard international definitions of the International Obesity Task Force Childhood Obesity Working Group. Design: Body mass index (BMI) cut-off points defining overweight and obesit y were applied to the individual BMI values in the two cross-sectional samp les. Setting: Australian community. Participants: 8492 schoolchildren aged 7-15 years (Australian Health and Fi tness Survey, 1985) and 2962 children aged 2-18 years (National Nutrition S urvey, 1995). Main outcome measure: Prevalence of overweight and obesity. Results: In the 1985 sample, 9.3% of boys and 10.6% of girls were overweigh t and a further 1.4% of boys and 1.2% of girls were obese. In the 1995 samp le, overall 15.0% of boys (varied with age from 10.4% to 20.0%) and 15.8% o f girls (varied with age from 14.5% to 17.2%) were overweight, and a furthe r 4.5% of boys (2.4%-6.8%) and 5.3% of girls (4.2%-6.3%) were obese. The pr evalence of overweight and obesity in the 1995 sample peaked at 12-15 years in boys and 7-11 years in girls. In schoolchildren aged 7-15 years, the ra tes represent a relative risk of overweight in 1995 compared with 1985 of 1 .79 (95% CI, 1.59-2.00) and of obesity of 3.28 (95% CI, 2.51-4.29). Compare d with previous estimates from these samples, the revised prevalence data a re slightly higher for the 1985 data and considerably higher for the 1995 d ata. Conclusion: The secular trend of increasing overweight and obesity in the d ecade from 1985 and the high prevalence rates in Australian children and ad olescents are a major public health concern.