World experts claim weight-loss surgery is a cost-effective option and should be recognised as a standard treatment.
By Thomas Moore, Health and Science Correspondent
Up to 100,000 people in the UK should be offered weight-loss surgery in the hope of curing their diabetes, world experts have said.
A leading group of international diabetes organisations, including Diabetes UK, says the evidence is now so strong that obesity surgery can also reverse type-2 diabetes that it should be considered a standard treatment option.
But prejudice in the medical profession, and pressure on NHS resources, means just 6,000 patients a year are having the procedure.
So far 11 scientific trials have shown that surgery to reduce the size of a patient’s stomach can reduce blood sugar levels below the threshold used to diagnose type-2 diabetes.
And one study showed almost all patients were able to stop taking insulin or other injectable medication to control their blood sugar.
The condition affects around 3.5 million people in the UK and is closely related to obesity.
The new guidelines, published in the journal Diabetes Care, say surgery should be considered in people with type-2 diabetes who have a body mass index (BMI) of 40 or over, and those with a BMI of at least 30 and blood sugar levels that aren't properly controlled by medication or lifestyle changes.
The guidelines are consistent with those already issued by the NHS watchdog NICE.
But clinical commissioning groups, which fund treatments, widely ignore the recommendations.
The operation costs at least £6,000, but because of future healthcare savings the money is generally recouped within two years.
Weight-loss, or bariatric surgery, can include reducing the size of the stomach with a gastric band or bypassing part of the stomach.
Prof Nick Finer, honorary professor at University College London and senior principal clinical scientist with Novo Nordisk, said: "Hopefully this will drive the NHS to support greater access to this treatment.
"Sadly in England less than 1% of people who might benefit are offered surgery and at a high level there is still a refusal to respond to the evidence so that the numbers of surgeries has been declining over recent years."
Type-2 diabetes is a major cause of kidney failure, blindness, nerve damage, amputations, heart attacks and strokes.
Fewer than half of patients manage to control their blood sugar levels with lifestyle changes or drugs.
Simon O'Neill of Diabetes UK said: "There is a wide body of evidence that shows surgery is an effective treatment option for type-2 diabetes and can be cost effective for the NHS.
"However, many people who stand to benefit from this potentially lifesaving treatment are missing out due to needless barriers to obesity surgery services.
Adrian Ault lost his job in 2014 because of ill-health brought on by obesity. He weighed 32 stone and suffered from type-2 diabetes.
He lost six stone to qualify for surgery, and another three stone since the operation five weeks ago.
He was told last week that he no longer had diabetes.
He told Sky News: "It was amazing. I got quite emotional.
"My mum had diabetes and it was the bane of her life. So it was something that worried me more than lots of the other things. So this was fantastic news to get."