In a three year study, patients who carried out the course, which also encouraged healthy lifestyle changes, successfully reduced the need for diabetic medication or insulin.

The team of British researchers found that patients who successfully completed the exercise and diet programme had no increase in their oral diabetes medication.

In addition, they were half as likely to progress to insulin as those who did not complete the programme and those who did not lose weight.

Type 2 diabetes is a progressive condition, but it was only the patients who did not successfully complete the programme that required increased amounts of oral diabetes medications over the subsequent three years.

The study further found that patients who successfully completed the programme - which costs less than £140 - also went on to maintain a healthier weight in the future than either those who failed to complete the course.

Experts said the findings showed simple lifestyle and dietary choices could help tackle the UK’s growing diabetes epidemic.

Dr Jennifer Logue, lead author of the study from the University of Glasgow, said: “This is the first real-world study to show that the lifestyle weight management programmes that we deliver in the NHS can have a long lasting meaningful clinical effect on type 2 diabetes.

“This study shows that the common assumption that the weight lost is quickly regained is not true. 

“Currently weight management programmes in the NHS are under-resourced and there is a lack of belief in their effectiveness by clinicians leading to low levels of referral, despite them being recommended by NICE.”

Dr Logue said the findings showed how effective the NHS Greater Glasgow and Clyde Glasgow and Clyde Weight Management Service lifestyle programme was.

She added: “Our hope is that this study will convince patients, clinicians and NHS managers that these inexpensive programmes can make a clinically significant difference to patients with type 2 diabetes.”

In light of the findings researchers believe that these kinds of lifestyle programmes - with healthy diets and exercise - may be even more effective than some pharmacological alternatives in treating type 2 diabetes.

Currently, around four million people in the UK have diabetes, with 90 per cent suffering from Type 2.

Type 1 is an auto-immune disease which cannot currently be cured. But Type 2 can be avoided by making lifestyle changes such as taking more exercise and eating a healthy diet. An estimated 550,000 people have Type 2 diabetes but are not aware of it.

But experts have warned that Britain is sitting on a diabetes timebomb with the number of prescriptions for type 2 sufferers rising by a third in five years from 26 million to 35 million.

Analysis of the shocking figures also revealed there are hotspots for the disease in London and Lincolnshire, with the London borough of Newham having twice the national average of prescriptions.

But experts say that with simple dietary changes, along with more exercise, could prevent huge number of Type 2 sufferers.

Last night, research bodies into the disease welcomed the findings.

Faye Riley, Research Communications Officer at Diabetes UK, said: “This encouraging research adds to the existing body of evidence that structured weight management programmes like this could help some people with Type 2 diabetes lose weight, maintain their weight loss and improve their Type 2 diabetes control.

“This research highlights the importance of making effective, accessible interventions available to everyone with Type 2 diabetes who may benefit from them.”

The new study examined records from the NHS 16-week lifestyle programme, which included a regime of diet, exercise and behaviour change.

The programme consisted of nine fortnightly classes.

Researchers defined ‘success’ as losing 5kg in that timeframe.

Patients could then choose to stay on for further weight loss and maintenance classes (1 per month) over the next year.

Those attending with Type 2 diabetes had to have a body mass index of 30 or above, in order to qualify to be referred to the programme.

To judge whether the programme was a success, researchers compared the successful group against those who attended and didn’t lose weight, or those who didn’t complete, or those who were never referred.

The researchers believe these kinds of programmes must now be better resourced so that more patients can achieve the defined ‘success’ weight loss of 5kg.

The study concluded that more and more patients with Type 2 diabetes would lose such weight if more investment in such programmes was made.

The courses must be designed so that those who attend can do so regularly while continuing with work and caring commitments, the paper added.

The new study is published in Diabetes Obesity and Metabolism.