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Prevention: Rationale

Rationale for obesity prevention

Last updated 23-05-2024

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.


1. Australian Bureau of Statistics. National Health Survey 2022. 2023 [Accessed March 2024]; Available from:
2. Australian Institute of Health and Welfare, 2021. Australian Burden of Disease Study 2018: Interactive data on risk factor burden. Available from
3. PwC Australia. Weighing the cost of obesity: A case for action. 2015. Available from:
4. Soleymani T, Daniel S, and Garvey WT. Weight maintenance: challenges, tools and strategies for primary care physicians. Obesity reviews : an official journal of the International Association for the Study of Obesity, 2016; 17(1):81-93.
5. Mihrshahi S, Gow ML, and Baur LA. Contemporary approaches to the prevention and management of paediatric obesity: an Australian focus. Medical Journal of Australia, 2018; 209(6):267-274.
6. Swinburn BA, Kraak VI, Allender S, Atkins VJ, Baker PI, et al. The Global Syndemic of Obesity, Undernutrition, and Climate Change: The Lancet Commission report. The Lancet, 2019; 393(10173):791-846.
7. McCrory MA, Suen VMM, et al. (2002). Biobehavioral Influences on Energy Intake and Adult Weight Gain. The Journal of Nutrition 132(12): 3830S-3834S.
8. Bleich SN, Cutler D, et al. (2008). Why Is the Developed World Obese? Annual Review of Public Health 29(1): 273-295.
9. Vandevijvere S, Chow CC, et al. (2015). Increased food energy supply as a major driver of the obesity epidemic: a global analysis. Bulletin of the World Health Organization 93(7): 446-456.
10. World Health Organization. ‘Best Buys' and other recommended interventions for the prevention and control of non-communicable diseases. Appendix 3 of the Global Action Plan for the Prevention and Control of Non-Communicable Diseases 2013-2020, 2017. Available from:
11. WHO, 2023, Acceleration plan to stop obesity
12. Commonwealth of Australia 2022. The National Obesity Strategy 2022-2032. Health Ministers Meeting. Available from:
13. Commonwealth of Australia 2021. National Preventive Health Strategy 2021-2030. Available from:
14. Sacks G, Mann D. Policies for tackling obesity and creating healthier food environments: scorecard and priority recommendations for the Australian governments, May 2023. Melbourne: Deakin University, 2023.
15. Ananthapavan J, Sacks G, Brown V, Moodie M, Nguyen P, et al. Assessing Cost-Effectiveness of Obesity Prevention Policies in Australia 2018 (ACE-Obesity Policy). Melbourne, Australia: Deakin University, 2018. Available from: