Over the next few weeks, we’ll be posting 10 myths about dieting from the article by Michael Mosley in The Times.
Claim 3 It is better to lose weight slowly and steadily, rather than rapidly
This is another of those claims that seems to be self-evidently true but which the obesity researchers behind Myths, Presumptions and Facts about Obesity describe as a myth. Or as they put it, “Within weight-loss trials, more rapid and greater initial weight loss has been associated with lower body weight at the end of long-term follow-up”.
Very-low-calorie diets (VLCDs), based on consuming less than 800 calories a day, have been used since the 1970s to induce rapid weight loss, but the assumption is that once you stop you will simply put it all back on. In a thorough meta-analysis, The evolution of very-low-calorie diets: an update, reviewers looked at the results of 6 randomised trials that had run for at least a year comparing very-low-calorie diets with standard low-calorie diets.
They found that the VLCDs led, not surprisingly, to much bigger weigh loss in the short term and though the dieters did, on average, later put back on much of the weight they had lost, so did those on the standard diet. In the long term there didn’t seem to be any significant difference between these approaches. The researchers point out that doing VLCDs can be more expensive but that “Cycles of weight loss and regain do not seem to have the adverse health and metabolic consequences once feared”.
An interesting recent development is the use of VLCDs (600 calories a day over several weeks) to try and improve blood glucose control in overweight type 2 diabetics. A small trial in Newcastle produced very positive results and larger trials are planned.
1:14 pm
26 Jun 14