According to the study, overweight and obese people can blame genetics and the global "feast" for their weight problem.
Jeffery Zajac, head of medicine at Austin Health in Melbourne, said he subscribed to the model that obesity was caused by genetic make-up.
"Diet and exercise will not result in permanent weight loss in most obese people," Herald Sun quoted Prof Zajac, as saying.
"We can't just blame fast food. Genetically we are designed to eat and store food.
"In a world where we are surrounded by feast not famine, we find it difficult to avoid overeating and to lose weight," Prof Zajac added.