Lying on an operating table at the BUPA hospital in Leeds is a 27 stone woman.

Richard Hannaford talks to patients who have had the operation

She's about to have her dearest dream realised as consultant surgeon Stephen Pollard makes her stomach smaller and creates a new loop by-passing much of her digestive system.

After two hours the operation is complete. Of the 200 patients who have undergone the procedure, all have lost weight and none have had any adverse reactions.

Mr Stephen Pollard is the only surgeon using the technique in the UK

Currently Mr Pollard is the only surgeon doing this work. He now sees patients from all over Britain - both privately and on the NHS.

Apart from their size what they all have in common is that they are all desperate.

"About a third of the patients referred to me are super obese - these are patients who are on average over 26 or 27 stone, and I've seen quite a lot over 30," Mr Pollard says.

"The heaviest I've seen to date is just over 40."

He says many of his patients had previously tried other standard procedures such as having their jaws wired, their stomachs stapled or having a balloon placed in their guts.

Barbara Izzard before the operation

They had all tried dieting, but to no avail, he says.

Sitting in her back garden in Oxford Barbara Izzard is looking at old photos of herself. She had the operation 18 months ago and is already eight stone lighter. It has, she says, changed her life.

"I love every minute of every day now.

"I've been married for 40 years and for 39 of those years I have been very heavy. Now I'm getting back to the weight I was when I got married."

The latest figures suggest that obesity is getting worse. Twenty per cent of women and 17% of men are clinically obese. And the figures for children are also alarming.

Now Barbara says the operation changed her life

At the offices of the British Nutrition Foundation, Amanda Wynne says we all need to do more exercise and eat more fruit and vegetables.

"I think it's very important that we all get physical activity into our daily lives.

"Whether that's just going for a walk or a cycle or doing some gardening doesn't really matter - we just need to get more active."

But that is not the answer for everyone.

At 45 Carol Mills is nearly three times her ideal body weight. It not only is affecting her health but limits her whole life.

She has never sat on an airplane - never been on holiday. Now she wants to have the operation which she believes will give her her life back.

"If I don't have this operation I'll just get bigger and bigger and bigger all the time. It's out of control," she says.