The number of people with diabetes has doubled in the last 15 years, with obesity fuelling the rise, a charity has warned.

Data analysed by Diabetes UK shows that in 2004/05 the number of people diagnosed with diabetes was 2.1 million, but by 2019/20 this had jumped to around 4.1 million.

A further 850,000 people are living with undiagnosed type 2 diabetes, a rise of 150,000 in the last year, meaning more than 4.9 million people are currently living with diabetes in the UK.

If this trend continues, there will be 5.5 million in the UK with diabetes by 2030, the charity said.

We want to help people understand their personal risk of type 2 diabetes and the first step is to complete our free Know Your Risk Tool today

It warned that obesity is fuelling type 2 diabetes, accounting for 80% to 85% of someone’s chances of developing the condition, with the number of obese people rising from 6.9 million to 13 million over the last 20 years.

The data has been released to mark the beginning of Type 2 Diabetes Prevention Week, from May 10 to 17, and aims to encourage people to use the free online Know Your Risk Tool to see if they have the condition.

Factors such as age, family history and ethnicity can increase a person’s likelihood of having diabetes, while studies have found that people of African-Caribbean, black African or south Asian descent are two to four times more likely to develop type 2 diabetes than those from a white background.

Chris Askew, chief executive of Diabetes UK, said: “The pandemic has shown with devastating clarity how diabetes puts you at increased risk of poorer outcomes when contracting the virus, yet we know that with the right support, up to half of type 2 diabetes cases − and the accompanying risk of developing life-threatening complications − can be delayed or prevented.

“This diabetes prevention week, we want to help people understand their personal risk of type 2 diabetes and the first step is to complete our free Know Your Risk Tool today.

“By taking just five minutes out of your day, you have the power to access information and support that could change your health for the better.”

NHS national clinical director for diabetes Professor Jonathan Valabhji said: “The evidence is clear that diabetes significantly increases the risk of dying from Covid and so it is now more important than ever that we focus our efforts on not just treating type 2 diabetes but preventing people from getting it in the first place.

“The NHS has already offered over 750,000 people at risk of type 2 diabetes support to lose weight on our world-leading diabetes prevention programme, and now as we start to see signs of normal life returning, there has never been a better time to make changes to your lifestyle – you can easily check your risk online and self-refer for NHS support.”