The county’s health chief said one in four people in Oxfordshire were now obese.

Oxfordshire’s health director Dr Jonathan McWilliam said the problem was putting a “significant burden” on the NHS in the county.

We have previously reported how obesity cost the county £143m in 2007 and predicted it would rise to £159m a year by 2015.

Dr McWilliam said: “Obese and overweight individuals place a significant burden on the NHS.

“Direct costs are estimated to be £4.2bn nationally and these will more than double by 2050.

“The costs to Oxfordshire’s primary care trust of treating diseases related to being overweight and obese are set to increase by approximately £1m each year.

“If current trends continue, the estimated annual costs to NHS Oxfordshire will rise to £159m in 2015.”

He said the NHS predicted it would deal with an additional 6,000 cases of diabetes and an extra 1,776 heart attacks over the next decade, which would cost £18.3m to deal with.

The fresh warning came in NHS Oxfordshire’s report, which said county’s increasing waistlines were not being helped by the fact threequarters of people in the county did not do enough exercise.

Last month, we reported rising levels of obesity had forced health chiefs to convert an ambulance to carry overweight patients.

An adult is classed as obese if they have a body mass index (BMI) of more 30 or more.

Meanwhile, NHS Oxfordshire said 85 per cent of high blood pressure and ten per cent of all cancer deaths among non-smokers were related to obesity.

The risk of developing type two diabetes is about 20 times greater for people who are very obese.

Dr McWilliam, who is employed by both NHS Oxfordshire and Oxfordshire County Council, said authorities needed to work together to tackle the problem.

He said the health trust and the county and city councils had made good progress in the past year by increasing access to physical activity programmes, including footpaths and cycle paths on town and city planning.

He added: “It should include a focus on the important role of GPs. Work with children and adults should be seamless and those at increased risk should be targeted.”

Lucy Brown runs slimming classes in North Oxfordshire and regularly receives referrals from GPs as part of an NHS scheme.

She said it was important to educate people about healthy eating.

She added: “Fruit and vegetables are cheap, but when you are walking around supermarkets you can see special offers on junk food and they are just as appealing.

“I think people just need to be better educated about the dangers.”

The report released yesterday also warned of the rising problem of alcohol abuse in the county.

Dr McWilliam said every month about 3,500 A and E admissions at the county’s hospitals were alcohol-related.

The report also said more than 11 per cent of all crime in Oxfordshire was alcohol-related, with criminal damage caused by drinkers costing £4.5m, violent assaults fuelled by alcohol costing £1.5m and serious sexual offences linked to alcohol costing £3.1m last year.

He said: “Alcohol is a deeply ingrained part of British culture.

“We need to raise awareness of the risks of alcohol and say to people to try to start with one or two alcohol-free days per week.”