Australia has been warned to address prevailing issues on obesity and depression based on the latest health report by the Organisation of Economic Co-operation and Development (OECD).

In its annual 'Health At A Glance' publication, the OECD reported that Australia ranks number four among the fattest nations in the world at 28.3%, behind the U.S. (36.5%), Mexico (32.4%) and New Zealand (28.4%).

"Obesity is a leading cause of diabetes and cardiovascular disease. Governments need to invest in cost-effective strategies to reverse the obesity epidemic," the organization said.

The report also warned the Australian government that the next generation may live shorter lives than expected if no action will be done.

Mike Daube of Curtin University is not surprised with the report as the country is in 'policy denial' regarding obesity.

"We aren't just fat," Prof. Daube told Fairfax Media. "We are on the medal podium - one of the fattest countries in the world. We have a top-class health system. We are smoking less, we eat a lot of fruit and vegetables and our life expectancy is now around 82. But much of this progress is being put at risk because of our dismal failure to deal with obesity."

The country also has the second highest prescription of antidepressants, with 89 users out of every 1,000 Australians.

Iain McGregor of University of Sydney noted the rise in antidepressant use indicates "something serious about the fabric of our society and other like societies."

"We all know someone whose life has been saved or turned around by medication, but if you have mild or moderate depression, or have had a couple of nasty life events, generally the data says you are better off seeing a psychologist," McGregor added.

The study also indicated higher incidents involving medical procedures in Australian hospitals. For instance, for every 100,000 surgery patients, 8.6 of them have foreign body left inside them by surgeons. In addition, women who give birth naturally are more likely to experience obstetric trauma than those who give birth via cesarean section.

The organization, however, reported some improvements in select sectors in the country's health system. Life expectancy at birth, for one, is now at 82 years, two years higher than the average life expectancy of all OECD member-countries.

Australia is also one of the top five countries with higher survival rates after a cancer diagnosis or heart attack - a strong proof of the country's high quality health system.