Steve Cox is now able to climb a stile in the Warwickshire fields near his home with slightly more ease than in the past. After years of being overweight, the 52-year-old dentist is far more enthusiastic about walking since he lost 25.4kg (four stone) during the summer.

Cox is evangelical about his recent experience at a private slimming club. The venture set him back £1,500 and involved a kind of benign dictatorship, whereby he could only eat the food given to him in shopping bags each week.

When he first weighed in, Cox was 119.3kg (18st 11lbs). Now he is 25.4kg lighter and would like to shed another couple of kilograms.

'For years, since my student days really, my weight has yo-yoed up and down and I've tried all kinds of diets but they never worked,' said Cox, from Southam, Warwickshire. 'But I thought I should give the new clinic a go because it seemed to have some kind of sound scientific basis.'

Cox went to the Healthier Weight Centre in Birmingham, where he had weekly meetings with a nurse who looked at his lifestyle and food diary.

The clinic's work is based on changing behaviour, so while weekly calorie intake is measured, physical activity is also strongly encouraged.

Every client is given a pedometer so they can build walking into their daily routine. At £1,500, the 12-week course is not cheap but that price includes food and all necessary medical checks, as well as follow-up advice.

Mr Cox feels it was money well spent: 'You could say it should be available on the NHS, but personally I think the health service should be spending its money on other priorities. After all, I'm the one that put the weight on, so it's my responsibility to get it off again, isn't it?'