SYDNEY -- More than half of all Australian women, two-thirds of men and one-fifth of children are overweight or obese, DPA quoted a leading obesity expert as saying on Wednesday.

Speaking ahead of the International Nutrition Symposium starting on Wednesday in Melbourne, Professor Phillip James, chairman of the International Obesity Task Force and advisor to the World Health Organisation, told ABC radio, "Australia is up there with the UK and the U.S. as one of the fattest nations."

The conference will release new Australian research which shows less advantaged families are more likely to suffer from obesity and are more likely to eat a high fat, high energy diet.

Professor Phillip James, chairman of the International Obesity Task Force and advisor to the World Health Organisation, said obesity was one of the unrecognized health issues facing the world.