The NHS is under attack for the excessive costs it incurs in treating diabetes patients, after it was found that one in seven hospital beds is occupied by someone with diabetes or related disabilities. This has pushed the cost to the NHS to a record £10 billion a year for treating the condition.

The illness is linked to lifestyle factors such as obesity, too little exercise, and an unhealthy diet. Campaigners warn that the ''eye-watering'' cost of diabetes care to the nation is going to get worse.

It already accounts for about 10 per cent of the total NHS budget, with most being spent on complications such as amputations and stroke. The costs will soar further over the next 20 years, when it is projected to soak up 17 per cent of the entire NHS budget, says a report.

It will also increase the costs of social care, while a further £9 billion is lost to the economy because of reduced productivity or those with diabetes being forced out of work altogether.

Some 3.8 million people in the UK have diabetes, including 600,000 who are unaware they have it. The total is predicted to rise to five million by 2025.

Nine in ten of those with diabetes have type-2, which occurs when the body gradually loses the ability to process blood sugar, leading to high levels which can damage organs and cause years of ill health.

A report by the charity Diabetes UK says the £10 billion the NHS now spends on diabetes care is too often being spent badly.

Those who are diagnosed late or do not receive timely care can find themselves having to spend extra days in hospital and suffering from kidney and nerve damage as a knock-on effect, running up huge bills for the NHS.

The report says only one in ten of those newly diagnosed are offered education on managing their condition. These new patients have a longer length of stay in hospital – on average by three days – and regularly experience medical mistakes, especially medication errors, and avoidable deterioration in their condition.

The report sets out a series of measures it claims will save the Health Service billions and improve care.

It says that better education on how to manage the condition can save £2,200 a patient, while a reduction in foot amputations – a traumatic and expensive complication of diabetes – could save hundreds of millions of pounds a year.

Diabetes can damage the eyes, heart, nerves, feet and kidneys, leaving many dependent on gruelling and costly dialysis machines. The vast majority of the £10 billion – around 80 per cent – goes on treating complications that may have been prevented if the patient had received good care in the first place.

Diabetes is known to be on the rise in India too, particularly in the increasingly prosperous middle and upper classes. However, no study has yet been carried out on the cost of the disease to the nation.