Ditch the clubs and just eat less says diet expert

Every year in Scotland and throughout the UK, tens of thousands of slimmers attend WeightWatchers meetings where dieters are weighed and encouraged to slim down to a target weight. It is now a major international company and every week around 1.3 million people attend 50,000 WeightWatchers meetings around the world. The joining fee is 9 and each weekly meeting costs 5.99.

But most of its income comes from its food range, which is now the UK's 14th largest grocery brand, outselling Nescafe, Philadelphia and Branston.

Dr Kirsty Kiezebrink, of the state-funded Health Services Research Unit, concedes that people who stick to the firm's dietary plans do lose weight but claims the majority then pile it back on again.

The Aberdeen University-based research fellow said: "You are not realistically going to live on those products forever. It doesn't educate you how to change your lifestyle.

"Unless you want to carry on giving WeightWatchers money you have got to come back to a normal, non-supported diet and you are likely to regain the weight that you lost. "

The expert in diet, appetite and body weight said the programme was costly and claimed the results were difficult to replicate once people left the group. She believes points-based dieting can leave people in a vicious circle of weight fluctuation and claims the popularity of "fast fix" diet schemes is actually contributing to the nation's growing obesity problems.

She said: "If weight loss is quick it will come back again. It should be about making changes which are slow, steady and achievable on a long-term basis. Otherwise it is just painful and pointless."

Kiezebrink insisted the best long-term results could be achieved with simple, cost-free steps. She said: "The only diet that I have found to be particularly effective is portion control. People get hung up on portion sizes, but my advice is, whatever you usually eat, have a bit less. Only do what is achievable, don't set yourself up to fail."

Last week WeightWatchers' programme was endorsed by a scientific study of hundreds of British slimmers which found that those who took part in a commercial diet club for three months lost twice as much weight as those given diet advice by their family doctor.

But Beat, the UK's biggest Eating Disorder Charity, also expressed concerns about the long-term effectiveness of commercial diet groups. Chief Executive Susan Ringwood said: "Most people regain the weight they lose within two years.Quick fixes that don't work just add to someone's sense of failure and can lead to the downward spiral of helplessness that can lead to more serious mental health issues."

Zoe Hellman, WeightWatcher's UK dietitian, claimed Kiezebrink's views were misleading. She said: "It is unfortunate this individual has chosen to perpetuate the perception that losing weight is a waste of time because you'll pile it all back on again. That isn't a useful or helpful public health message.

"It's misleading to just say things don't work. There are things that do work and Weight Watchers has evidence to show that we're one of them."