Our bodies encourage us to regain lost weight

This means that public health messages encouraging people to eat healthy food and to exercise are unlikely to have any long-term impact on obese people, Professor Joseph Proietto from the University of Melbourne said.

Public health messages have been successful in controlling epidemics of infectious diseases and reducing the incidence of smoking, but obesity is more difficult to control, Prof Proietto said.

“After weight loss, changes in both energy expenditure and in hunger-controlling hormones encourage weight gain,” he said.

“It appears that once someone becomes obese, that state is physiologically defended. This newly discovered biology explains the high failure rate of obesity management.

“Several studies have shown that, although obese people who make the effort can achieve and maintain significant weight loss for 1-2 years, the weight is usually regained in the longer term.”

In contrast, long-term outcomes can be achieved through bariatric surgery (procedures that reduce the size of the stomach), with patients maintaining weight loss after 10 years, Prof Proietto said.

“In the absence of safe, effective pharmacological agents that can be used long term, bariatric surgery is the most successful intervention for sustained weight loss,” Prof Proietto said.

In an accompanying Editor’s Choice, MJA Editor Dr Annette Katelaris called for legislated public health measures to improve food intake.

The Medical Journal of Australia is a publication of the Australian Medical Association.

The statements or opinions that are expressed in the MJA reflect the views of the authors and do not represent the official policy of the AMA unless that is so stated.

CONTACT:     Professor Joseph Proietto                                 0419 210 007

                    Mr John Heselev                                              0434 315 490

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