Obesity has this year overtaken smoking as Australia’s leading risk factor contributing to disease, according to a national study.

The Australian Burden of Disease Study 2024, released today by the Australian Institute of Health and Welfare, estimates the millions of years of healthy life Australians lose because of injury, illness or premature death.

The report measures over 200 diseases and injuries and provides estimates of how much of the burden of each can be attributed to 20 individual risk factors such as alcohol use, physical inactivity, poor diet, overweight or obesity and tobacco smoking.

“Overweight, including obesity, overtook tobacco use as the leading risk factor in 2024,” AIHW spokesperson Michelle Gourley said.

Gourley said the change was largely due to a substantial fall of 41 per cent in tobacco use since 2003.

“This fall is likely due to declines in smoking prevalence and burden rates from some of the major linked diseases, such as lung cancer and chronic obstructive pulmonary disease,” she said.

The study found that an estimated 8.3 per cent of total disease burden in 2024 was due to overweight (including obesity) and 7.6 per cent was due to tobacco use (excluding vaping). This was followed by dietary risks (4.8 per cent) and high blood pressure (4.4 per cent).

Alcohol use and illicit drug use were the leading risk factors for young males aged 15-24, while shockingly, child abuse and neglect was the leading risk factor contributing to burden for young females of the same age.

Gourley said Australians lost an estimated 5.8 million years of healthy life due to living with disease and dying prematurely in 2024.

“Over one-third of the total burden of disease and injury in Australia in 2024 could have been avoided or reduced due to modifiable risk factors included in the study,” she said.

When looking at rates of total disease burden, there was a 10 per cent decrease between 2003 and 2024 after adjusting for population ageing. 

However, living longer did not equate to living better, with a gap between Australians’ longevity and their years of healthy life.

“While Australians are living longer on average, years lived in ill health are also growing, resulting in little change in the proportion of life spent in full health,” Gourley said.

“This contributes to the growing demand and pressures on the health system and services,” she added.

As in previous years, cancer was the leading group of diseases causing causing a health burden in 2024 at 16.4 per cent. Of these cases, 91.3 per cent were fatal and 8.7 per cent non-fatal.

The leading specific diseases were coronary heart disease (5.5 per cent), dementia (4.5 per cent), back pain and problems (4.3 per cent), anxiety disorders (3.9 per cent) and chronic obstructive pulmonary disease (3.7 per cent).

Males were overall of poorer health than women, driven by rates of coronary heart disease. For women, the leading cause of disease burden was dementia.

Sadly, mental health conditions, and suicide and self-inflicted injuries were leading contributors of ill health among young people, especially males aged 15 to 24.

In girls of the same age, anxiety disorders, depression and eating disorders were most prevalent.

For younger Australians, aged five to 14, autism spectrum disorders, asthma and anxiety disorders were common.

Gourley said the burden of disease was the gold standard approach for measuring the impact of illness, injury and death.

“This information provides an important evidence base to inform health policy and service planning,” she said.