IF LIFE expectancy at birth is any measure, Australians are some of the healthiest people on earth.
United Nations figures show that Australian women have the third highest life expectancy in the world, at 84 years, and our men come in fourth at 79 years.
Australia's high life expectancy, expected to continue its slow rise, is a measure that adds to our wellbeing on The Age Lateral Economics Index.
But the index's authors considered that life expectancy alone was inadequate in assessing people's health over the course of their lifetime. They also counted as a positive the fact that fewer Australians were being hospitalised for preventable conditions, such as those prevented by vaccines or managed through lifestyle interventions (such as heart disease, asthma and diabetes).
Australian Institute of Health and Welfare figures show that in 2009-10, 30 of every 1000 hospital admissions were for preventable conditions, down from 32 in 2004-05.
But two other conditions emerged as having such a significant and widespread impact on individuals that they negatively affected the whole country's wellbeing - mental health and obesity.
Director of the World Health Organisation's Collaborating Centre for Obesity Prevention at Deakin University, Boyd Swinburne, said research had found obesity had an effect on quality of life equal to a major physical disability such as being blind or deaf. ''Quality of life includes mental and physical health, social wellbeing and personal self-esteem. Obesity affects all of those,'' he said.
The index authors started with the 9 per cent of gross domestic product that Australians spend publicly and privately on health - considering that a clue to its relative importance in our lives. They then made adjustments based on the four measures they considered further illuminated our state of health: life expectancy, preventable hospitalisations, mental health and obesity.
They used treatment rates to track how well mental illness - which affects 20 per cent of the population - was being managed. High rates of mentally ill people did not have a GP treatment plan, but those who did grew from 14.3 per cent in 2004-05 to 17.7 per cent in 2009-10. And obesity - which affected almost 25 per cent of the population in 2007-08, up from 20 per cent in 2001 - emerged as a huge drain on the nation's wellbeing.
Index author Nicholas Gruen said previous research had quantified the amount of money you would need to pay a person to generate a percentage improvement to their wellbeing.
So by looking at the huge effect that people say mental health and obesity have on their wellbeing - and matching that to the amount of money you would need to pay them to compensate for it - the index authors weighed their impact.
Untreated mental illness and obesity were considered so significant that even accounting for the gains made elsewhere - in life expectancy and reducing preventable hospitalisations - health was an overall drag on our national wellbeing.