It has always been thought that crash diets are incredibly unhealthy and do more harm than good. New research from Tufts University in Massachusetts says that this is in fact false and crash diets can actually work better than slow and gradual weight loss. Susan Roberts, professor of nutrition and psychiatry at Tufts, says the latest research from her lab shows that “sensible, healthy crash diets actually do as well for long-term success as slow diets and, for some people, can actually work better”.
She distinguishes between good and bad crash diets, however. The one she advocates goes further than the usual 1,500 calories a day typically advised for women to lose 1lb per week, but is not extreme, never dipping below 1,200 calories for women (or 1,800 for men). “We studied two groups, in which we cut either 10% or 30% of calories, and tried to keep them at it for a year,” she explains. “In the end, they were in a similar place — the 30-percenters definitely did not do worse, despite having a more stringent programme.”
What is more, she adds, people who get tempted easily may be better candidates for fast, strict diets than gentle weight loss: “A small calorie cut can work for the sensible crowd, but seems to almost backfire for people who get tempted by food. Dis-inhibited eaters (a psychological term referring to people who give up on diets easily when presented with food opportunities) actually did really badly on the 10% diet.”
“Despite the hype about slow diets being better, there has actually been very little research into whether losing weight fast or slowly works better in the long run,” argues Roberts. “The trouble with slow diets is people tend to feel they are getting nowhere and give up. Fast keeps you excited and feeling like you’re making progress.”
Other experts take a very different view and insist any kind of diet is unhealthy and a waste o time “Diets depend on failure,” says the psychotherapist Susie Orbach, who has explored women’s attitudes to eating in such books as Bodies. “They need to fail, otherwise there would be no repeat customers.”