The study found that those who place their lives in the hands of fate were less likely to change their lives by their own actions, leading to conditions including obesity.
Their outlook meant that they exercised less, ate less healthily and smoked and drank more than those who believed their life was in their own hands, the 'Daily Mail' reported.
A team from the Melbourne Institute of Applied Economic and Social Research looked at the diet and exercise habits of more than 7,000 people and compared the results to their personality types.
"Our research shows a direct link between the type of personality a person has and a healthy lifestyle," said Professor Deborah Cobb-Clark.
She suggested that the findings could have implications for the obesity epidemic, with psychology playing a more important role.
"The main policy response to the obesity epidemic has been the provision of better information, but information alone is insufficient to change people's eating habits," Cobb-Clark said.
"Understanding the psychological underpinning of a person's eating patterns and exercise habits is central to understanding obesity," she added.