The number of people with diabetes in the UK is now more than 3.2 million, with last year featuring the biggest jump in cases since 2008.
National Health Service figures show 3,208,014 adults are now diagnosed with the condition. Around 850,000 more people have diabetes without knowing it.
The rise is being fuelled by cases of type 2 diabetes, which is linked to obesity and unhealthy lifestyles.
Last year, there were 163,000 more people across the UK who have been diagnosed with diabetes compared to 2012.
This is the biggest yearly increase since 2008, when the jump was 167,000. It means six per cent of UK adults are now diagnosed with diabetes.
In 1996, the number of people diagnosed with both types of diabetes was thought to stand at about 1.4 million.
While the overall rise could be partly down to improvements in recording and diagnosis, experts at Diabetes UK, which analysed the figures, said the sharp rise over the last decade - fuelled by type 2 - shows no signs of slowing down.
The charity warned that more needs to be done to target those at risk of type 2 as well as improving healthcare for all people with diabetes.
The figures come after Cardiff University researchers said last week that insulin use has trebled over the last 20 years in the UK, driven by high rates of type 2.
Type 1 diabetes, which accounts for around 10 per cent of all cases, usually develops in childhood.
Baroness Young, chief executive of Diabetes UK, said: "The big increase in the number of people with diabetes confirms that we are in the middle of an unfolding public health disaster that demands urgent action.
"It is frightening to think that one in 17 people you walk past in the street has been diagnosed with the condition.
"Firstly, we need more focus on preventing type 2 diabetes, as this is the only way we can bring the rapid rise in diabetes cases under control."
She said diabetes accounts for 10 pence of every pound the NHS spends but healthcare is patchy and inconsistent.
Around 80 per cent of NHS spending on diabetes goes on treating complications of the condition, such as amputation, kidney failure, heart disease and stroke.
Diabetes UK says as many as seven million more people are at high risk of developing type 2 diabetes and, if current trends continue, an estimated five million people will have diabetes by 2025.
