Worldwide, there are more than 1.5 billion overweight adults, including 400 million who are obese. In Australia, it is estimated more than 50 per cent of women and 60 per cent of men are either overweight or obese.
Although restriction of diet often results in initial weight loss, more than 80 per cent of obese dieters fail to maintain their reduced weight. Obese people may regain weight after dieting due to hormonal changes, a new study has shown.
Professor Joseph Proietto from the University of Melbourne and Austin Health said the study revealed the important roles that hormones play in regulating body weight, making dietary and behavioral change less likely to work in the long-term.
"Our study has provided clues as to why obese people who have lost weight often relapse. The relapse has a strong physiological basis and is not simply the result of the voluntary resumption of old habits," he said.
Dr Proietto said although health promotion campaigns recommended obese people adopt lifestyle changes such as to be more active, they were unlikely to lead to reversal of the obesity epidemic.
"Ultimately it would be more effective to focus public health efforts in preventing children from becoming obese."