Oral Presentation Australian & New Zealand Obesity Society 2015 Annual Scientific Meeting

Prevalence of morbid and severe obesity in Australian children age 7-15 years, 1985 to 2007 (#42)

Aimee Jones 1 , Louise L Hardy 2 , Louise A Baur 3 , Sarah P Garnett 1 3
  1. Institute of Endocrinology and Diabetes, The Children's Hospital at Westmead, Sydney, NSW, Australia
  2. Prevention Research Collaboration, School of Public Health, University of Sydney, Sydney, NSW, Australia
  3. The Children's Hospital at Westmead Clinical School, University of Sydney, Sydney, NSW, Australia

Background: Increasing rates of obesity in children, as measured by BMI, may be slowing or even plateauing. However, there is concern that the BMI distribution curve has shifted further to the right, indicating that the proportion of children with morbid and severe obesity is increasing. This study reports the prevalence of morbid and severe obesity in Australian children in 1985, 1995 and 2007.

Methods: Three Australian cross-sectional surveys of measured height and weight in 7 to 15 year olds: Australian Health and Fitness Survey 1985 (n= 8,486), National Nutrition Survey 1995 (n= 1,541) and the National Children’s Nutrition and Physical Activity Survey (n= 2,585).  The IOTF cut-point was used to define morbid obesity. Severe obesity class 2 was defined as BMI ≥120% and <140% of the 95th percentile (CDC2000) or a BMI ≥35, and severe obesity class 3 as BMI ≥140% of the 95th percentile or a BMI ≥40.

Results: Between 1985 and 2007 the prevalence of morbid obesity increased from 0.2% to 1.8%, class 2 severe obesity from 0.3% to 1.9%, and class 3 from 0.1% to 0.4%. Children with morbid obesity represented 11.3% of children with obesity in 1985 and increased to 24.2% in 2007 (P=0.002). Children with severe obesity represented 19.3% of children with obesity in 1985 and increased to 31.1% in 2007 (P=0.014). The proportion of children who classified as obese, morbidly or severely obese was not significantly different between age and sex groups.

Conclusion:  Prevalence of morbid and severe obesity among children with obesity is low, but has significantly increased from 1985 to 2007. Children with morbid and/or severe obesity have a greater risk of serious health consequences compared with children who are overweight or obese and require tertiary intervention.  Failure to treat these children will have significant implications for the individual child and community.