Many people go on a diet at some point in their lives, often after an over-indulgentChristmas or to slim down for a summer holiday when the bikini beckons.

Many fad diets have been tried over the years, from Atkins to Low GI to special drink replacement meals, some with side effects and some without. Most people know at least one person, often a friend or family member, who has been on and off diets for most of his or her adult life. One week, they decline your offer of a sandwich, “ I’m on the low-carb diet.” The next, they read the number of calories in the Kinder Bueno that is half way to your mouth. And the week after that, they wolf down a family-size portion of chips. It’s hard to keep up.

But some people take dieting too far and severely restrict their daily food intake over a short period of time, known as crash dieting. In the past, nutritional studies found that when you crash diet, you actually only lose muscle and water. When you stop, you regain the weight and it could mess up your metabolism.

However, new research from Tufts University in Massachusetts suggests that crash diets can actually work better than slow weight loss for some people. Susan Roberts, professor of nutrition and psychiatry at Tufts, says that “sensible, healthy crash diets actually do as well for long-term success as slow diets and, for some people, can actually work better.” There are good and bad crash diets, however. The one she advocates never goes below 1,200 calories a day for women and 1,800 for men.

Not everyone has seen the results of the research on a positive light. Dr Peter Rowan, an eating-disorder consultant from the Cygnet hospital in London, warns that dieting and eating disorders often go hand in hand. “The large majority of patients with anorexia and bulimia have the illnesses triggered by weight loss”, he said. “Even a sensible weight-loss diet can trigger an eating disorder in someone who is vulnerable, but there is evidence to suggest that the more severe the weight loss, the more likely the diet is to trigger an eating disorder.”

The most recent diet in the press in the form of a pill and claims to induce massive weight loss. Orlistat – brand name Alli – works by blocking the absorption of fat in the body, and is aimed at adults with a Body Mass Index (BMI) of 28 or more. However, there are some unpleasant side-effects. If they continue to eat fat, they will experience diarrhea.

For some people, over-eating has an emotional trigger. This is also a form of eating disorder. They overeat when they feel stressed, upset or when they don’t feel they have control over an issue in their lives. For these people, finding the cause for their overeating is the key to stopping it.

Dr. Hensrud, an expert in nutrition at the Mayo Clinic in Minnesota, warns that too many people look for a quick-fix. “In general weight loss is difficult and people are always looking for the easy answer”, he said. What we all know deep down – and often refuse to believe – is that eating well and doing exercise is the healthiest way to lose weight.

By Bex