Overweight (including obesity) and physical inactivity are key risk factors impacting disease burden in Australia. In 2018, 8.4% and 2.5% of Australia’s total disease burden was attributable to these risk factors, respectively. The aim of this project was to investigate the burden saved in the year 2030 under hypothetical scenarios of improving population exposure to these risk factors.
This project uses comparative risk assessment methodology applied to the Australian Burden of Disease Study to estimate population attributable fractions that indicate the proportion of disease burden attributable to a risk factor. Exposure in the population to overweight (including obesity) and to physical inactivity was adjusted to reflect different levels of improved disease risk from these factors, including scenarios of reductions in body mass index (BMI) and of additional exercise.
If everyone in the population at risk in 2017–2018 were to reduce their BMI by 1kg/m2, and these rates were maintained to 2030, disease burden and deaths attributable to overweight (including obesity) could fall by 11% (60,400 DALY) and 10% (2,300 deaths), respectively, compared with the stable scenario. This decreases further to 23% (123,000 DALY) and 22% (5,300 deaths) in the scenario where BMI is reduced by 2 kg/m2.
If everyone in the population at risk did an extra hour of moderate-intensity activity (such as taking a brisk walk) per week, attributable burden and deaths could fall by 16% (28,300 DALY) and 13% (1,500 deaths), respectively, compared with the stable scenario.
These results suggest that, if population-wide changes to overweight (including obesity) and physical inactivity occur and are maintained to the year 2030, there would be large improvements in population health, including gains in population-level quality of life and cost reductions for the health system.