THE number of weight-loss operations being performed on the NHS in Scotland has declined by a fifth, despite surgeons arguing that doing more would save the health service money in the long-run.

Evidence has shown that bariatric surgery, which shrinks the size of a patient's stomach, is an effective intervention to help severely obese patients return to a normal weight, sustain it long-term and in many cases reverse Type 2 diabetes.

This has led to calls from bariatric specialists for the UK NHS to increase the number of patients undergoing procedures such as gastric bands.

Read more: Leading bariatric surgeon says 'vast majority' of obese patients 'can't cook simple meal' 

However, figures obtained under freedom of information by the Herald show that health boards in Scotland are now performing fewer weight loss operations than they were four years ago.

According to the data, the number of operations being carried out has fallen fairly steadily from 259 in 2013/14 to 2011 in 2015/16, and 205 in 2017/18, a reduction of 21%.

The Scottish Government stressed that there has been no change in the criteria for bariatric surgery since 2012, and that it is up to individual health boards to set their own local spending priorities.

Tam Fry, chair of the National Obesity Forum, said: "Pressure on budgets mean that a lot of bariatric surgery is being refused, and that is a short-term catastrophe.

"Surgeons are absolutely right that there should be more rather than less, because the people who are being denied this surgery will continue to get further obese and then start to develop co-morbidities if they don't already have them.

"It's not a question of the 20% reduction being engineered because people are getting thinner, it's because people are not getting the bariatric surgery that they require basically down to cost. That is a short-term measure and a really regrettable one.

"I'm getting this all over [the UK] - it is the ridiculous diktats that are handed down by the commissioning authorities that they regard obesity still as not being a disease, as being a personal problem and therefore you should be sorting it out instead of expecting the NHS to do it for you."

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Between them NHS Ayrshire, Grampian, Lothian, and Forth Valley spent £1,151,993 last year providing 110 operations - an average cost of £10,473 per patient.

That is around twice the cost to the NHS of a hip or knee replacement, and compares to around £9000 for a heart bypass, but being obese will also substantially increase a person's likelihood of requiring one of these procedures.

It comes after figures for England, published at the weekend, revealed that the number of obese patients undergoing surgery to replace knees and hips has soared six-fold, from 6,191 in 2009-2010 to 41,761 in 2017-2018. The figures included seven teenage girls.

Obesity is also the second biggest avoidable cause of cancer, after smoking.

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The figures come after surgeons warned the UK NHS should be performing thousands more weight-loss operations every year.

France, with a population similar to that of Britain, carries out 37,000 obesity operations a year, compared with just 5,000 in the UK.

Two countries with far smaller populations – Belgium and Sweden – perform 12,000 and 7,000 respectively, while Italy does 8,000.

Speaking at an international conference on obesity surgery, Marco Adamo, chair of the National Bariatric Surgery Register, said: "The UK data is overwhelming – surgery makes a difference to people’s health and we want commissioners to acknowledge this and act accordingly.

"Severe and complex obesity is a serious, lifelong condition associated with many major medical conditions, the cost of which threatens to bankrupt the NHS.”

In Scotland, patients aged 18 to 44, with a BMI between 35 and 40, who have developed Type 2 diabetes in the last five years are given first priority for bariatric surgery on the NHS. Heavier patients, with diabetes and a BMI of 40 to 50, are next in line.

The picture varies between health boards, but Lothian, Greater Glasgow and Clyde, and Ayrshire and Arran are among those to record the steepest declines in activity.

NHS Lothian has gone from performing 52 weight-loss operations in 2013/14 to 23 last year, and in NHS Ayrshire and Arran it has fallen from 48 to 39.

Excluding patients undergoing maintenance procedures to remove or adjust an existing gastric band, the number of bariatric surgeries carried out in NHS Greater Glasgow and Clyde has dropped from around 50 to 30.

However, in Fife, Scotland's obesity hotspot, the number of operations have roughly doubled, to 16 last year.

A Scottish Government spokeswoman said: “The current guidance on bariatric surgery has been in place since 2012. NHS boards decide, taking account of national and local priorities, how best to utilise the funds allocated to them to meet the health care needs of its local population.

“We are committed to tackling obesity. Earlier this year, we published our delivery plan to create a Scotland where everyone eats well and has a healthy weight.

"As part of this plan we will invest an additional £42 million over five years to give people with, or at risk of, type 2 diabetes support and better access to effective weight management services.

“We’re also consulting on restricting the in-store promotion and marketing of food that is high in fat, sugar or salt but with little or no nutritional benefit to tackle our nation’s damaging relationship with junk food.”