Currently, doctors can test for diabetes only by taking blood glucose readings that show whether the disease is already present.
The test, being created at Nottingham Trent University and Cardiff University, will use a sensor in a special kind of "nano-material", which traps specific molecules - or biomarkers - that indicate disease years before Type 2 diabetes develops.
The specific biomarkers involved are being kept a closely guarded secret for now, but once a prototype test has been developed, trials will take place. "Due to factors such as people living longer, sedentary lifestyles and obesity, the number of people with Type 2 diabetes is growing by 7 per cent a year," said Bob Stevens, a professor at Nottingham Trent University's School of Science and Technology.
"It's hugely important that steps are taken to address this major health issue, and we have the technology here to help make a difference.
"It will probably give the result in different shades of grey. If you got light grey, it might mean you should stop eating that cake, but a darker reading might show you need to do a lot more exercise.
"We will be able to give people an opportunity to change their diet and lifestyle, and make a positive impact to healthy ageing. Not everyone will be motivated to make the changes but if even 1 per cent change because of it, it could have a huge impact.
"In addition, the savings to the NHS could be enormous."
The team hopes the device will be on shelves or in doctors' surgeries within three years.
Type 2 accounts for about 90 per cent of all diabetes cases in Britain and the number of sufferers has risen by 59.8 per cent in a decade, equating to an extra 1.2?million adults.
Diabetes UK predicts that if current trends continue, five million people will have diabetes by 2025.