Australian study links hormones to weight gain
Obese people may regain weight after dieting due to hormonal changes, a University of Melbourne and Austin Health study has shown.
The study, which was undertaken in collaboration with La Trobe University, in Melbourne, was published in the New England Journal of Medicine today.
According to the study’s findings, although restriction of diet often results in initial weight loss, more than 80 per cent of obese dieters fail to maintain their reduced weight.
The study involved 50 overweight or obese adults, with a Body Mass Index (BMI) of between 27 and 40, and an average weight of 95kg, who enrolled in a 10-week weight loss program using a low energy diet. Levels of appetite-regulating hormones were measured at the end of the program and one year after initial weight loss.
The results suggested that following initial weight loss of about 13 kgs, 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 5kgs during the one-year period of study.
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.
Professor Proietto 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. 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.”