WEIGHT loss operations will almost treble in Scotland's largest health board area under plans to shake-up the treatment of obesity.

More than half the population of NHS Greater Glasgow and Clyde is classified as overweight or obese and, following expert analysis, doctors will be expected to increase the number who undergo bariatric surgery to shrink stomach capacity.

The National Planning Forum, which helps standardise NHS treatment across Scotland, has advised NHS GGC to increase the number of bariatric operations from 40 to 108 a year.

Bariatric surgery includes gastric band fitting, which divides the stomach in two, and gastric by-pass surgery when a small pouch at the top of the stomach is created using special staples and connected directly to the small intestine. Both help patients to feel fuller quicker.

The health board has agreed to re-organise their specialist weight management service in order to offer more of these procedures. They are also streamlining access to Weight Watchers which is available on the NHS in the region to patients who meet the necessary criteria. Already 80 groups are open to NHS patients across six council areas, but board papers say: "Prevalence of overweight and obesity is such that whilst it is not feasible or appropriate to provide service to everyone affected, the service capacity requires to be increased significantly to address a greater proportion of the affected population."

The papers go on to say NHS GGC needs to ‘rebalance’ its current specialist weight management service (GCWMS) in order to meet an increase in surgical activity as well as delivering increasingly intensive interventions with heavier and more complex patients."

Naveed Sattar, professor of metabolic medicine at Glasgow University, has called for the number of people undergoing weight loss surgery to double and welcomed the increase planned.

He said: "A lot of people out there still think 'why don't the really heaviest people diet and lose 20 stone' but if it was easy people would be doing it."

Once people reached a certain size, he said, their stomachs were so stretched it became almost impossible for them to lose weight.

That put them at risk, he continued, of premature cancer and health problems related to high blood pressure and diabetes.

Professor Sattar said: "If you give them the surgery you can lengthen their life, improve their quality of life and reduce their risk of major conditions such as premature heart disease and cancer and in many cases reverse diabetes."

He described it as "cost effective" because the resulting weight loss was likely to reduce patients' need for healthcare long term and may help them return to work.

He also expressed sympathy for patients who found it hard to resist widely available, tempting food, describing it as "a form of silent abuse."

However, patients have to demonstrate motivation to change to be considered suitable candidates for bariatric operations.

Professor Sattar said: "We have to be careful. We do not want it to be widely available meaning people think 'I will eat what I want because I will get my surgery at some point.'"

Dr Amelia Crighton, interim director of public health for NHS GGC, said there was "recognition that bariatric surgery is a good option for some patients with a BMI over 35 with one or more co-morbidities (long term conditions)."

She added: "If we have evidence that bariatric surgery is the most effective intervention for certain types of patients, where they are suitable for that, we will make sure it happens."

GPs in NHS GGC will be able to let patients refer themselves to Weight Watchers on the NHS using a telephone number, under the streamlined system. Medical records will be checked to ensure eligibility.