Rationale for obesity prevention
Increased global supply of energy-dense processed foods, together with improved food distribution and marketing, is recognised as a major driver of obesity. An effective strategy to address rising rates of obesity in Australia needs to address deeper causes rather than simply relying on individual-level behaviour change. Systems-based policy actions have the potential to produce long-term improvements in obesity rates.
Key Evidence
Two-thirds of Australian adults are now living with overweight (34.0%) or obesity (31.7%)
The cost of obesity in Australia is estimated at more than $11.8 billion a year
Reversing the obesity epidemic requires systems-based policy actions
Obesity in Australia
Two-thirds of Australian adults are now living with overweight (34.0%) or obesity (31.7%).1 The prevalence of overweight and obesity has risen steadily among Australian adults in recent decades, driven mainly by increased rates of obesity.1 (For more detail, see Trends.)
Obesity impacts
Excess weight and obesity have a negative effect on many systems in the body and accounted for 8.4% of the total burden of disease in Australia in 2018.2 This represents the impact of people dying early and living with illness due to conditions caused by excess weight, which was surpassed only by smoking (8.6%) as a modifiable risk factor for ill health.2 (For more detail, see Impacts.)
In addition to the health impacts of overweight and obesity, there are significant economic impacts. The cost of obesity in Australia has been estimated at more than $11.8 billion annually, including $5.4 billion in direct costs (such as healthcare) and $6.4 billion in indirect costs (such as lost productivity).3 These costs will continue to build in line with rising rates of overweight and obesity in Australia.
Obesity environment
Despite the emergence of some promising pharmaceutical therapies, there are few effective, long-term treatments for individuals to manage obesity.4 To date in Australia, interventions have largely employed individual-level approaches to influence behaviour change to prevent obesity.5 Rising obesity rates are not a failure of collective willpower, however, and an effective strategy to address the issue needs to recognise and address deeper causes. No country has successfully reversed its obesity epidemic because the systemic drivers of obesity continue largely unabated.6
Based on analyses of food supply and physical activity data in the United States7 and other high-income countries,8 researchers have concluded that increased kilojoule intake is the driving force behind rising obesity rates. Declines in work-related physical activity have been gradual and largely predated a rapid rise in obesity rates. On the other hand, food supply data shows an association between an increased supply of kilojoules and rising average body weight across many countries.9 Researchers have found that increased food energy supply alone is sufficient to explain increases in population weight.9
Overconsumption of kilojoules is associated with food systems that have become more industrialised, globalised, and dominated by large multi-national companies that produce ultra-processed foods.6 These products are based on relatively inexpensive commodity ingredients, they are often highly palatable, heavily marketed, cheap, and contain excessive amounts of energy, fat, sugar or sodium.
Obesity prevention strategies
In this environment, systems-based policy actions have the potential to produce long-term changes to address obesity. Government measures such as regulations to reduce exposure of children to marketing of unhealthy food and brands, front-of-pack warning labels, and fiscal policies (such as taxes on sugary drinks) can help to constrain supply-driven consumption of unhealthy foods.6
Various authorities have proposed evidence-based policies to address the obesity epidemic. These include a series of reports from the World Health Organization (WHO), including WHO’s ‘Best Buys’ and other recommended interventions for the prevention and control of non-communicable diseases, which presents policy options to address unhealthy diet and disease areas including cardiovascular disease, diabetes and cancer.10 Most recently, the WHO has published the WHO Acceleration Plan to Stop Obesity.11 In Australia, major government strategies that include a focus on obesity are the National Obesity Strategy 2022-203212 and the National Preventive Health Strategy (2021-2030)13 and the Australian Food Policy Index14 provides an assessment of the extent to which Australian governments are implementing globally-recommended policy for obesity prevention, and includes priority recommendations for Australian governments to tackle obesity.
To assist with priority setting, a comprehensive multi-year study, Assessing Cost-effectiveness of Obesity Prevention Policies in Australia, conducted economic evaluations of 16 interventions and found they were all likely to be cost-effective approaches to addressing obesity in the Australian population.15 It was estimated that 11 of the interventions would not only produce cost-effective health benefits, but also save costs in the long-term. Interventions determined to produce cost savings in the long term included:
- increasing the price of alcohol*
- a tax on sugar-sweetened beverages
- kilojoule labelling at fast food outlets, and
- restrictions on price promotions of sugar-sweetened beverages.
The following sections of the Obesity Evidence Hub set out the evidence in three key areas for obesity prevention:
Across these areas, there are a range of promising policies that decision-makers could implement to deliver substantial health benefits as part of a comprehensive response to obesity.
* Alcohol makes a significant contribution to energy intake and high alcohol intake is linked to weight gain.