New figures have revealed that the number of adults with diabetes has increased by 6% since 2009, while obesity rose by a similar amount.
The results indicate that 5% of people are being treated for diabetes and 10% are receiving help for obesity.
Diabetes UK has described the rise in people with the conditions as "shocking".
The charity has called on the government to follow through its promises to tackle health problems through prevention.
GP practices across the UK compiled the data, which show that 2.8 million people over the age of 17 have diabetes in the UK, which is a 150,000 increase since last year.
Meanwhile, there are now more than 5.5 million obese people over the age of 16 – a rise of more than 265,000.
Type 2 diabetes – which the vast majority of sufferers have – is strongly linked to being overweight or obese, leading a sedentary lifestyle and eating an unhealthy diet, the charity said. About 90% of diabetics (2.5 million people) have the type 2 variety of the condition.
Simon O'Neill, Diabetes UK director of care, information and advocacy, said: "The obesity-fuelled type 2 diabetes epidemic is a clear example of where the new coalition government's rhetoric of tackling health problems through prevention must be turned into action.
"Failure to act now means a bleak future of spiralling NHS costs and worsening public health.
"Diabetes is serious. If not diagnosed early or poorly managed, it can result in blindness and amputation or a shortened life expectancy from heart disease, stroke and kidney failure."
Copyright © Press Association 2010
Your comments (terms and conditions apply):
"Surely the only shocking thing here is that people are shocked? Perhaps it is time we stopped pussyfooting around and quasi medicalising it and just call it like it is, fat or very fat not a medical problem in itself so up to individuals to eat less and move more, which - no matter how you dress it up - is the only way to lose weight. Not easy I know I could go home and slump in front of the telly some nights too but I don't and I almost never eat plastic pre-prepared meals. The information is out there, time people looked at themselves long and hard and took responsibility for their own and their families health per your other article" – Name and address withheld