October 15th, 2014
Another Diet Myth Exploded: Gradual Weight Loss No Better Than Rapid Weight Loss
Once again, a popular weight loss myth has been exploded. It has been widely believed that weight loss, which is nearly always difficult to maintain, is even less likely to be sustained if it’s the product of a rapid weight-loss regimen. This belief is even enshrined in current guidelines. Now a study published in The Lancet Diabetes & Endocrinology provides no support for this view. Instead, the study suggests that although long-term weight loss remains elusive regardless of the diet, short-term weight loss is actually greater with rapid weight loss.
Australian researchers randomized 200 obese adults to either a 12-week rapid weight loss diet (with Optifast) or a 36-week gradual diet. Participants who lost at least 12.5% of their weight then participated in the second phase of the study, in which they were placed on a 144-week maintenance diet.
In the first phase of the study, 50% of people on the gradual diet and 81% of people on the rapid diet achieved the 12.5% weight loss goal. Both groups struggled considerably in the second phase: 71.2% in the gradual diet group and 70.5% in the rapid diet group regained most of the weight they had shed in the first phase. In both groups, patients who successfully completed phase 1 lost a little over 14 kilograms in the first phase but then gained back all but 4 kg in the second phase.
In an accompanying comment, Corby Martin and Kishore Gadde write that the study shows that “a slow and steady approach does not win the race, and the myth that rapid weight loss is associated with rapid weight regain is no more true than Aesop’s fable.” They cite a number of potential short-term advantages of very low calories diets and note that these diets are now well formulated and provide adequate protein and essential micronutrients. They are “safe if used under expert supervision,” the write.
“Across the world, guidelines recommend gradual weight loss for the treatment of obesity, reflecting the widely held belief that fast weight loss is more quickly regained,” said the first author of the paper, Katrina Purcell, of the University of Melbourne, in a press release. “However, our results show that achieving a weight loss target of 12.5% is more likely, and drop-out is lower, if losing weight is done quickly.”
(Editor’s note: The senior author of the paper served as an adviser to Opitfast’s manufacturer from 2005 to 2010.)