But it's also due to increased risk factors.
"They include being an unhealthy weight, not getting enough exercise and not eating the right amount of fruit and vegetables," Ms McGlynn said.
The AIHW data shows that over the last decade the number of adults not getting enough exercise rose from 69 to 72 per cent.
Women are less likely to exercise than men.
In 2008, some 69 per cent of men failed to get 30 minutes of moderate activity on most days of the week. By contrast, 76 per cent of women didn't get enough exercise.
Australians are also struggling to maintain a healthy diet.
Some 91 per cent of adults don't eat at least five serves of vegetables every day - up from 86 per cent four years earlier.
Forty-nine per cent of the population don't eat two serves of fruit compared with 46 per cent less than half a decade previously.
As a result, in 2008 some 61 per cent of Australians adults were overweight or obese compared to 57 per cent in 1995.
Men are generally fatter than women.
While the number of overweight males has declined from 46 to 43 per cent since 1995 the number of obese men has escalated 6.3 percentage points to 25.2 per cent.
By contrast, 31 per cent of women are overweight (up from 30 per cent in 1995) while 23.4 per cent are obese (up 4.4 percentage points since 1995).
But there is some good news - the number of deaths associated with diabetes is down.
Between 1997 and 2007 the diabetes-related death rate among all Australians fell by 18 per cent.
"This may be a result of better diabetes management," Ms McGlynn said.
"However, the increasing number of Australians with diabetes is still a cause for concern, as is the number of Australians with modifiable risk factors for diabetes."
- AAP