After 20 years of rapid increases in life expectancy at birth, the rate of growth in Australia is now falling behind most other high-income nations, meaning better control of health risk factors such as obesity will be needed if further life expectancy increases are to be achieved, research shows.

Published today by the Medical Journal of Australia, researchers from the University of Melbourne School of Population and Global Health have analysed data for Australia and 26 other high-income countries from 1980-2016.

Researchers found from 1981 to 2003, life expectancy at birth increased rapidly in Australia, both in absolute terms, and in comparison, with other high-income countries.

For males, the difference in life expectancy between Australia and the other 26 countries increased from +0.7 years to +2.3 years over this period. For females, the difference in life expectancy increased from +0.9 years to +1.3 years.

University of Melbourne Rowden-White Chair of Global Health and Burden of Disease Measurement Alan Lopez said the main contributor to greater increases in life expectancy for males in Australia than in western Europe was lower mortality from ischaemic heart disease.

"Compared with the United States, mortality from ischaemic heart disease, cerebrovascular disease, and transport-related injuries was lower," Laureate Professor Lopez said.

Since 2003, researchers found life expectancy has increased more slowly for both sexes than in most other high-income countries, mainly because declines in mortality from cardiovascular disease and cancer have slowed. For males, it was +2.3 years in 2015, and females, +1.1 years.

"Together with the high prevalence of obesity, this suggests that future life expectancy increases will be smaller than in other high-income countries," Professor Lopez said.

University of Melbourne researcher and co-author Tim Adair said this slowing should concern public health policy makers.

"Life expectancy in Australia is among the highest in the world, a testament to boldly progressive public health interventions over several decades," Dr Adair said.

"However, there are several major barriers to marked increases, including the notably higher mortality of more recent birth cohorts and the comparative failure of efforts to reduce levels of overweight and obesity.

"Other high-income countries have greater scope for reducing the prevalence of smoking. As a result, our high global ranking with regard to life expectancy at birth is unlikely to be maintained unless new strategies for reducing mortality associated with specific behaviours are developed and deployed effectively."