Sydney: Though following strict diets mostly brings down weight, over 80 percent of obese dieters fail to maintain their reduced weight. The reason? Hormonal changes.
Worldwide, there are more than 1.5 billion overweight adults, including 400 million who are obese.
Joseph Proietto, professor at the University of Melbourne, said: "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.
The study involved 50 overweight or obese adults with a BMI (height to weight ratio) between 27 and 40 and an average weight of 95 kg who enrolled in a 10-week weight-loss programme using a very low energy diet, the New England Journal of Medicine reports.
Levels of appetite-regulating hormones were measured at baseline, at the end of the programme and one year after initial weight loss, according to a Melbourne statement.
The results showed that following initial weight loss of about 13 kg, the levels of hormones that influence hunger changed in a way which would be expected to increase appetite.
These changes were sustained for at least one year. Participants regained around five kg during the one-year period of study.