Contrary to most research that recommends long term weight loss diets, the University of Melbourne paper, published in The Lancet Diabetes & Endocrinology, has suggested that ‘crash diets’ may be more effective.
For the study, 200 obese participants were randomly assigned to either a 12-week rapid weight loss program with a low calorie diet (450-800 calories a day), or a 36-week gradual weight loss program as recommended by current dietary guidelines. ‘Crash dieters’ aimed to lose an average of 1.5kg a week, while participants on the gradual weight loss scheme were to lose 0.5kg a week.
The results were surprising.
Around 71 per cent of subjects in both groups ended up regaining similar amounts of weight within three years, regardless of the diet program they were assigned.
“Global guidelines recommend gradual weight loss for the treatment of obesity, reflecting the widely-held belief that fast weight loss is more quickly regained,” said co-author and dietician Katrina Purcell.
“However, our results show that an obese person is more likely to achieve a weight loss target of 12.5 per cent weight loss, and less likely to drop out of their weight loss program, if losing weight is done quickly.”
Lead researcher Joseph Proietto said global guidelines may need to be reviewed as a result of this study.
“This randomised study highlights the urgent need for committees that develop clinical guidelines for the management of obesity to change their advice,” he said.
But health researchers around the world remain divided.
“This is an important and well conducted study. It shows clearly that the common claim that more rapid initial weight loss is associated with more rapid regain is false,” said Susan Jebb, Professor of Diet and Population Health at the University of Oxford.
“This is important because it will enable professionals to recommend a broader range of treatment options so that people may be more likely to find the one that is best suited to their lifestyle.”
Naveed Sattar, Professor of Metabolic Medicine at the University of Glasgow, said both groups were essentially participating in ‘rapid loss’ diets, and further research is needed.
“This is not really a surprising result, since I would suggest that both conditions represent more rapid weight loss than desirable,” he said.
“One must remember that weight gain in many who are obese has occurred over years and reversal may need to be relatively slow so that the body’s brain and gut homeostatic systems that regulate appetite have time to reset. The present study suggests that too rapid a change in weight lead many to fail with weight loss in the longer term.
“What we need is further studies to identify individuals who may be more successful with rapid weight loss vs. moderate weight loss vs. slow weight loss. Clearly, different people react in different ways to different regimens and we have little knowledge in deciding who may succeed best with what strategy.”
What do you think of this study? Has ‘rapid weight loss’ diets worked for you? Or do you think long term diets are more effective?
