According to the latest Australian Burden of Disease Study 2024 by the Australian Institute of Health and Welfare (AIHW), being overweight or obese has overtaken smoking as the primary risk factor contributing to disease burden in Australia for 2024.

The report evaluates the health impacts of injuries, illnesses, and premature deaths, quantified as years of healthy life lost, across more than 200 diseases and injuries.

It also examines the contribution of 20 specific risk factors, including alcohol consumption, physical inactivity, unhealthy diets, obesity, and smoking, to the overall disease burden.

AIHW spokesperson Michelle Gourley noted that Australians lost an estimated 5.8 million healthy years of life in 2024, with over one-third of this burden potentially preventable through lifestyle adjustments.

The shift in risk rankings is largely attributed to a 41% decrease in smoking-related disease burden since 2003. This reduction aligns with declining smoking rates and corresponding decreases in major smoking-related diseases, such as lung cancer and chronic obstructive pulmonary disease (COPD).

By 2024, overweight and obesity accounted for 8.3% of the total disease burden, surpassing smoking at 7.6% (excluding e-cigarettes). Other significant risk factors included dietary risks (4.8%) and high blood pressure (4.4%).

For younger Australians, risk factors vary by gender and age group. Among males aged 15–24, alcohol and illicit drug use posed the greatest risks, while childhood abuse and neglect were the leading risk factors for females in the same age group.

Between 2003 and 2024, overall disease burden rates decreased by 10% after adjusting for population aging. Fatal disease burden dropped significantly by 26%, while non-fatal burden increased by 7%. Despite longer life expectancies, the proportion of life lived in poor health has remained largely unchanged, contributing to growing pressure on healthcare systems.

Cancer remains the leading cause of disease burden in 2024, contributing 16.4% of the total. Notably, 91.3% of cancer burden was attributed to fatal outcomes, while 8.7% was non-fatal. Coronary heart disease was the single largest cause of burden (5.5%), followed by dementia (4.5%), back pain and related problems (4.3%), anxiety disorders (3.9%), and COPD (3.7%).

Men bore a greater overall disease burden across all age groups, primarily due to higher rates of fatal diseases. The leading causes of disease burden also differed between genders; coronary heart disease was the top contributor for men, while dementia led for women.

Among young Australians, mental health conditions and self-harm were significant contributors to disease burden. For males aged 15–24, self-inflicted injuries accounted for 12% of the burden, followed by anxiety disorders (10%) and depression (7%). In the same age group, females experienced a higher burden from anxiety disorders (17%), depression (12%), and eating disorders (7%).

For children aged 5–14, the primary contributors differed by gender. Boys faced the highest burden from autism spectrum disorders and asthma, while asthma and anxiety disorders were the leading causes for girls.

Gourley emphasized that disease burden is a "gold standard" for understanding the impact of diseases, injuries, and deaths. These findings provide critical evidence to inform public health policies and healthcare service planning.