Almost six people a day are being diagnosed with diabetes across Sussex with a rising number of new cases linked to a growing obesity problem.
More than 2,100 Sussex residents discovered they were diabetic in the last year, according to research by Diabetes UK.
The new figures mean that more than one in 14 of the county's population now have the condition.
The charity says most new patients have Type 2 diabetes which is linked to risk factors such as being overweight, having a large waist, being over 40 or having a close family member with diabetes.
Diabetes is just one condition linked to obesity which in total is expected to cost NHS trusts in the county £460 million by 2015.
In Brighton and Hove, there were 158 new diabetes cases, bringing the total for the city up to 13,554.
In West Sussex, cases rose by 1,168 to 51, 591 and in East Sussex they rose by 822 to 37,037.
Diabetes UK is now urging people in Sussex to make sure they are aware of the risk factors and be assessed if any of these apply to them.
It says around 80% of cases of Type 2 could be delayed or prevented through making healthy lifestyle changes.
The charity is also concerned many people wrongly think diabetes is a relatively mild condition and so do not see the need to find out more about it.
However, it can lead to devastating health complications such as blindness, amputation, stroke and heart attacks, and ultimately to early death.
Jill Steaton, Diabetes UK's south east regional manager said: “It is alarming the number of people with diabetes has gone up and addressing this situation needs to be one of the top health priorities.
“Given the increase in diabetes cases is mainly due to a sharp rise in Type 2 diabetes, we need to get much better at preventing cases of Type 2.
“I know we all have busy lives and that thinking about future health can be uncomfortable, but it is only if people grasp the nettle and get their risk assessed that we can start to bring the rise in diabetes to an end.”
David Brindley from Brighton and Hove City Council's public health team said: “Obesity is a major risk factor for developing Type2 diabetes and having a healthy weight and proper nutrition is key in preventing and controlling the disease.
“The new Brighton and Hove Health and Wellbeing Strategy has prioritised this objective and sets out a programme of activities to encourage people of all ages to adopt a healthier life style. “ City-wide projects to improve activity include free swimming for under 17s, Healthwalks and exercise-referral schemes.
There is also weight management support in community and health care settings, including cooking and healthy eating courses.
NHS Health Checks are available for people aged 40 to 74 years at most GP practices.
People can check their diabetes risk at a Tesco pharmacy, their GP surgery, or at www.diabetes.org.uk/risk.