The bill for treating people with diabetes across Sussex is soaring.

More than 1.1 million prescriptions for the condition were handed out in the county last year at a cost of £24.4 million. This is a rise of more than 5% on the year before.

Doctors have blamed the increase on ever-rising levels of obesity as people eat unhealthily and become less active.

Work across Sussex to cut obesity levels and reduce the chance of developing diabetes includes free swimming sessions for children in Brighton and Hove, exercise and healthy eating programmes and health checks to assess whether people are at risk.

This includes looking at a patient’s ethnicity, age, waist measurement and body mass index.

Diabetes UK chief executive Barbara Young warned that, unless the growing number of people developing the condition is checked, diabetes could bankrupt the NHS within a generation.

She said: “We need a government-funded awareness-raising campaign on the risk factors and symptoms of Type 2 diabetes and we need to get much better at identifying people at high risk so they can be given the support they need to prevent the condition.

“The existing NHS Health Check, which everyone between the ages of 40 and 74 should be getting, has the potential to do this but has so far been poorly implemented.

“It is only by improving this that we can end the steep rise in the number of people with diabetes and so begin to bring the spiralling financial cost of the condition under control.

“Until this happens, the increase in spending on diabetes-related medicines is inevitable when you consider that they are vital to reduce the risk of complications such as blindness, amputation, kidney failure and stroke and of premature death.”

The figures, published by the NHS Information Centre, show there were 154,598 prescriptions issued in Brighton and Hove between April 2011 and the end of March at a cost of £3.2 million.

The NHS in West Sussex spent £13.4 million on 562,367 prescriptions, while in East Sussex 392,823 prescriptions were sent out, costing £7.8 million.

Late onset diabetes, or Type 2 diabetes, affects around 90% of people who have the disease.

It is caused by the body not producing enough insulin or not using what it produces effectively.

An NHS Sussex spokesman said: “Obesity is one of the factors behind the increase in Type 2 diabetes nationally.

“In Brighton and Hove there are a number of key programmes working to tackle this rise both through prevention and early identification.

“Patients needing additional lifestyle support, either to prevent the onset of diabetes or to manage and improve their existing condition, can be referred to different services across the city, including Brighton and Hove health trainers, Zest Exercise Referral Scheme, Shape Up, and Mind, Exercise, Nutrition... Do It!”