Karyn has waited four years for the operation

The 31-year-old wants surgeons to reduce the size of her stomach to help her lose weight.

But, like many patients in a similar position, she has been forced to wait.

With a �7,500 price tag, stomach reduction surgery is not always available on the NHS.

However, Karyn is adamant that the operation should be available to those who need it.

"I deserve a quality of life as much as anyone else does," she says.

"I get angry. I get low. I think I could have had the surgery years ago and had my life back.

"This is a disease. It is not self-inflicted. I did not just bring it on myself and decide to get fat. I don't stuff food down my neck."

Dr Jack Miller, a consultant at Dr Gray's Hospital in Elgin, in Scotland, also believes the surgery should be more widely available.

"We have a growing group of people who have a potentially fatal disease.

Brian lost 20 stone as a result of surgery

"We have a mechanism to reverse this and the cure is surgery," he says.

Brian Emslie is one of those who has gone under the surgeon's knife.

He weighed 34 stone before his operation. Now he weighs just 14 stone.

He believes the surgery can save the NHS money in the long run.

"If we're going to spend money on the problems that obesity causes like diabetes and heart disease, then why not treat the problem first?"