Technical Paper 1:
Obesity in Australia: a need for urgent action
2. New evidence on obesity in Australia
Table of contents
- 1 - Executive summary
2 - Obesity in Australia- 3 - Obesity prevention
- 4 - Potential initiatives
- Conclusion
- References
Addendum for October 2008 to June 2009- 1. New evidence on global perspectives on obesity
- 2. New evidence on obesity in Australia
- 3. New studies on the impact of obesity
- 4. New initiatives for obesity prevention and control
- 5. Strengthen, upskill and support primary healthcare and public health workforce to support people in making healthier choices
- 6. Maternal and child health
- 7. Disadvantaged communities
- 8. The National Aboriginal and Torres Strait Islander Nutrition Strategy and Action Plan (NATSINSAP) 2000–2010
- 9. Build the evidence base, monitor and evaluate effectiveness of actions
- References
Trends and scale of the problem
The results of two recent national surveys involving measured height and weight data were released in 2009. Results of both surveys indicate rises in obesity and overweight among male and female adults and children compared with comparable earlier data.[12]Prevalence of overweight and obesity in adults
The height and weight of adults and children was measured in the 2007–08 National Health Survey for the first time since 1995. Preliminary results suggest that overweight and obesity prevalence in adults has continued to increase. Data from the 2004–05 health survey indicated that 62% of men and 45% of women were overweight or obese,[13] continuing to rise from 2001 levels when 58% of men and 42% of women were overweight or obese (both surveys were based on self-reported height and weight).[14] Results from the 2004–05 survey showed that, for men, those in the 45–54-year age group had the highest rates of obesity (23.2%), while those in the 55–64-year age group had the highest rates of overweight (45.9%). For women, those in the 55–64-year age group had the highest rates of obesity (21.7%), while overweight was highest among those aged 65–74 years (30.8%).[13]Prevalence of overweight and obesity in children
Of particular concern is the increasing prevalence of overweight and obesity in children. Results from the National Children’s Nutrition and Physical Activity Survey (conducted February–August 2007) based on measured height and weight found that 23% of 2–16-year-old children were classified as overweight or obese (6% as obese and 17% as overweight), while 72% of 2–16-year-olds were classified as normal weight.[15]Recent trend data
Comparison of the National Children’s Nutrition and Physical Activity Survey data with data from previous studies shows a clear and disturbing upward trend in overweight and obesity rates in children over the last 20 years. Analysis of overweight and obesity levels among young Australians from comparable age groups at three time points over more than 20 years, using the same internationally accepted definitions of childhood overweight and obesity, is presented in Figure 1. These data indicate the change in overweight and obesity levels among 7–15-year-old Australian children between 1985, 1995 and 2007.Top of Page
As illustrated, the prevalence of overweight and obesity in boys aged 7–15 years has risen from 11.0% (95% CI 10.99–11.01) in 1985 to 20.0% (95% CI 19.97–20.03) in 1995, and 23.7% (95% CI 23.68–23.72) in 2007. In 7–15-year-old girls, the prevalence of overweight and obesity has increased from 12.2% (95% CI 12.19–12.21) in 1985 to 21.5% (95% CI 21.47–21.53) in 1995, and 25.8% (95% CI 25.78–25.82) in 2007.[16] While further data from a greater number of points in time are required to identify national trends more comprehensively, this analysis clearly indicates a rising trend in overweight and obesity for 7–15-year-old boys and girls between 1985, 1995 and 2007.
Figure 1:
Prevalence of overweight and obesity in Australian children aged 7–15 years, 1985–2007.[16]
* Data weighted for age, gender and region.
Children at special risk
In the Technical Report we described some significant differences which have been observed in overweight and obesity prevalence for children from different cultural backgrounds. For example, among adolescents, those most likely to be obese (four to five times more likely) were boys and girls of Pacific Islander or Middle Eastern/Arabic background.[17]There is also evidence that obesity and overweight is also an issue for Indigenous children.[18, 19] For example, the school-based study conducted by O’Dea in 2006 among 7889 6–11-year-old children across Australia found that obesity rates were higher for Indigenous boys than Anglo/Caucasian boys.[20] Indigenous children and adolescents aged 6–11 years were 1.4 times more likely to be obese than non-Indigenous Australians of the same age group.[20]
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Data from 2004–05 for 15–19-year-olds indicate that Indigenous teenagers were more than twice as likely (2.6 times) to be obese as non-Indigenous teenagers. Similar proportions of Indigenous and non-Indigenous teenagers were overweight but not obese.[20]
This study conducted by O’Dea also found that students in the most disadvantaged schools had higher rates of overweight and obesity than students in the least disadvantaged schools. The social gradient was greater for obese children than for overweight (excluding obese) children.[20]
There is some evidence that children from South East Asian backgrounds may have a significantly higher risk of high systolic blood pressure (SBP) with increases in obesity indices compared to those of Australian origin. A study examining the relationship between obesity and blood pressure in school-aged children from South East Asian backgrounds in Sydney found that in nine-year-old children, SBP increased 1.51 mm Hg for each of BMI increase for South East Asian children compared to 1.05 mm Hg for Australian children.[21]
Children’s nutrition and physical activity levels
The National Children’s Nutrition and Physical Activity Survey was the first national survey of Australian children’s nutrient intake since 1995 and the first national children’s physical activity survey since 1985.[15] Food, beverage, dietary supplement intake, activity patterns and physical measurements (weight, height and waist circumference) were recorded in 4487 children aged 2–16 years. Key findings included:[15]- Only 22% of 4–8-year-olds, 14% of 9–13-year-olds and 5% of 14–16-year-olds met the dietary guidelines for vegetable intake.
- A large proportion of children did not meet the recommendations for fruit intake: 61% of 4–8-year-old boys and girls and 51% of 9–13-year-olds met the requirements, compared with only 1% of 14–16-year-olds.
- The majority of children in each age group met the estimated average requirements for all of the assessed nutrients (for example, calcium, protein and iron) except for calcium. The majority (82–89%) of 12–16-year-old girls did not meet the estimated average requirement for calcium.
- The consumption of sodium in all age groups exceeded the recommended upper level of intake.
- Few 9–16-year-olds met the guidelines for electronic media use (around one-fifth). Girls met the guidelines more often than boys, and younger children more often than older children.
- Most 9–16-year-olds met the guidelines for moderate-vigorous physical activity every day. Girls met the guidelines less often than boys and there was a drop-off with age, extremely marked in older girls (13% of 14–16-year-old girls compared with 33% of 9–13-year-olds met the guidelines using the ‘all days’ method.)
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For free play, sport and active transport, girls reported lower levels of moderate-vigorous physical activity than boys. The results showed that the overall amount of moderate-vigorous physical activity decreased by about 10 minutes per day with each year of age.[15]
Few of the 9–16-year-olds met the guidelines for electronic media use (no more than two hours a day for entertainment). Only 19% or almost one-fifth met the guidelines using the most days method. Girls met the guidelines more often than boys, and younger children more often than older children. The proportion of children who met the guidelines every day out of four days of surveying was only 7%: 4% of 9–16-year-old boys and 9% of 9–16-year-old girls.[15]