Crash dieting may be more effective than steady weight loss programmes, a study has found.
Although most health experts and dietitians agree that long-term diets are more effective, the research suggests the opposite could be true.
An Australian trial followed 200 obese adults, half of whom were encouraged to lose 12.5 per cent of body weight within 12 weeks, and half who were allowed 36 weeks.
The researchers found that eight out of 10 people assigned to the rapid weight loss programme achieved their goal compared with just 50 per cent of the steady dieters "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 Katrina Purcell, the lead author on the paper from the University of Melbourne.
"However, our results show that achieving a weight loss target of 12.5 per cent is more likely, and dropout is lower, if losing weight is done quickly."
The number of people who regained weight after three years was also the same in both groups, 71 per cent, suggesting that crash dieting is better than gradual weight loss in the short term and no worse in the long term.
The researchers suggest that losing weight quickly motivates dieters because they see rapid results. Very low calorie crash diets also usually cut out carbohydrates, which usually fuels the body and therefore forces the body to burn fat more quickly.
Prof Susan Jebb, professor of diet and population health, University of Oxford, said: "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.
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."
However, some British experts suggested that losing weight over 36 weeks may be considered too fast to be considered very gradual weight loss.
Prof Tom Sanders, professor emeritus of nutrition and dietetics, King's College London, said it was unfortunate that seven out of 10 of the volunteers had regained their weight within three years.
"The challenge is not losing weight but sustaining weight loss," said
The study was published in The Lancet: Diabetes and Endocrinology.
