It’s a disease affecting millions of people in the UK – and sufferers are increasingly in their 20s or even younger. But it is possible to bring it into remission

Daniel Halliday says that being diagnosed with type 2 diabetes was one of the best things that ever happened to him. That’s because before receiving his diagnosis in October 2017, Halliday was depressed and housebound. He had become agoraphobic after being mugged at knifepoint in 2014, and was unable to work. On a typical day, he would wake up, play video games and eat: fried breakfasts, pizza, Pringles and sweets. Oh, and Greggs.

“I’ve always said that Greggs was one of the major contributors to my diabetes,” Halliday sighs.

At his heaviest, he weighed 136kg (21st 6lb) and had a 42-inch waist.

The diabetes diagnosis came as a shock. At first, Halliday, a 34-year- old NHS worker from Thornby, Northamptonshire, went into denial. “I thought: ‘I’m going to eat whatever I want, I don’t care.” But an unrelated health scare in March 2018 gave him the jolt he needed. Halliday started venturing outside the house, to the end of the street at first, then further. He eliminated fatty, carbohydrate-rich and processed foods from his diet – no more pasties and crisps. He started playing badminton and football.

The pounds fell off – he now weighs 95kg (15st) and his diabetes is in remission. More importantly, Halliday got his life back. “It shook me out of my bad lifestyle. It was a blessing in disguise. It made me realise how much of my life I was wasting by not living it to the full.”

Halliday was able to manage his diabetes through diet and exercise, because he has type 2 diabetes. Not to be confused with type 1 diabetes, an autoimmune condition which is not associated with lifestyle, type 2 diabetes is very often linked to obesity and inactivity. Three out of five cases of type 2 diabetes are preventable, but the consequences can be severe. People with diabetes can go blind, have heart attacks or strokes, or require amputations. The life-expectancy of someone with type 2 diabetes is reduced by a decade. It is a horrible, frightening disease – which is why Kelly Perrin, a 31-year-old finance worker from Rushden, Northamptonshire, burst into tears when she was diagnosed in January. “I knew it was serious,” she says.

Facebook Twitter Pinterest Kelly Perrin. Photograph: Kelly Perrin

Although it was once believed to be an inevitably degenerative disease, the good news is that a landmark 2017 paper from researchers at the University of Glasgow and the University of Newcastle found that patients who lost significant amounts of weight – about 15kg – were able to send their type 2 diabetes into remission. Yet despite the fact that we know how to avoid type 2 diabetes – and how to send it into remission – numbers continue to soar.

Diabetes is a global epidemic. According to the World Health Organization, 422 million people had diabetes in 2014, compared with 108 million in 1980. Ninety per cent of people with diabetes have type 2, compared with 8% who have type 1, and 2% with rarer forms of the disease. In the UK, 5 million people are projected to have type 2 diabetes by 2025. The cost to the NHS is colossal: £10bn a year is spent treating diabetes, one-tenth of its budget.

And record numbers of young people are being diagnosed with the disease. According to research from the University of Leicester and the University of Melbourne, one in eight people diagnosed with type 2 diabetes in the UK are aged between 18 and 40. This epidemic of young people being diagnosed is of great concern because, until recently, diabetes was thought to be an old person’s disease. “We’re seeing children with type 2 diabetes,” says Dr Faye Riley of Diabetes UK. “It’s incredibly worrying. A few years ago, that didn’t exist.”

The reason type 2 diabetes is on the rise is that we are getting fatter and becoming more inactive. Ninety per cent of adults with type 2 diabetes are overweight or obese, and obese adults are five times more likely to be diagnosed with diabetes than those who are not.

“People are consuming too much sugar, salt and saturated fat, and they aren’t reaching the recommended levels of physical activity,” says Riley. Environmental factors also play a part: our increasingly sedentary lifestyles, and readily accessible, cheap processed food. “We live in an unhealthy society where it’s not always easy for people to make healthy choices,” Riley explains. Perrin struggles to resist the confectionery aisle. “Sugar is literally everywhere – it’s in the chocolates by the till in the supermarket, in nice bright colours.”

“Nowadays, they say you should have your five a day,” says Emma, a 34-year-old parent from Cumbria. She was diagnosed with type 2 diabetes at 28. “There was nothing like that when I was young. We all grew up on cheese on toast and chips and beans, so that’s what I fed my kids.”

Emma had her first child at 18 – and money was tight. “We lived off benefits for a while. You went for the cheapest option, which was usually a bag of chips or cheese on toast.” After her diagnosis, Emma learned about nutrition. “I feed my kids better now,” she says. “But the damage is done for me.”

Not everyone who develops type 2 diabetes is overweight. There is also a genetic component, and BAME communities are more susceptible. Sian Bailey, 25, a teacher from the Isle of Sheppey, Kent, was diagnosed in June. A dress size 10, Bailey is slim – but she blames her poor diet for her diagnosis. “I ate for convenience rather than eating healthy foods … I’d pick up the easiest, cheapest food.” Bailey would eat three takeaways a week, usually McDonald’s or Chinese food.

She is determined to manage her condition through diet. “I’m only 25. I’ve damaged my body so much already. I want to do the best I can so I don’t end up in hospital.”

Sending your type 2 diabetes into remission using diet alone takes serious discipline. But the alternative – a lifetime on medications, which don’t always work – is worse. “Patients can be taking 10 or even 12 drugs which don’t control all their symptoms or prevent disease progression,” says Prof Mike Lean of the University of Glasgow, co-author of the 2017 study that showed type 2 diabetes could be reversed through diet. “The pain from nerve damage can be awful. It progresses with infections, ulcers, amputations, blindness, kidney failure and dementia. Patients are often in hospital for months on end.”

In order to reverse a type 2 diagnosis using diet, patients should eat 600 calories a day for six weeks. The so-called Newcastle Diet advises patients to consume three diet shakes a day, to take them up to 600 calories in total, with a further 200 daily calories of non-starchy vegetables permitted to supplement the diet. In tests conducted at Newcastle University, seven out of 11 people who followed this diet were free of diabetes within three months.

It is important to note that they are not cured of diabetes – the disease only goes into remission. Should they regain the weight, the diabetes may come back. “If you can lose enough weight, you can get rid of the extra fat that is upsetting your liver and affecting the way your pancreas functions,” says Lean. “Things go back pretty much to normal. The best way to avoid complications from diabetes is to not have diabetes.”

University lecturer John Thomas, 42, from Bangor, is one success story. After being diagnosed in 2015, Thomas was prescribed the blood-sugar and insulin-modulating drug metformin. One day, he heard Dr Michael Moseley talking about how type 2 diabetes can be reversed on the radio. “I filed his name away in the back of my mind, thinking: ‘I must look him up’,” he says. A few weeks later, his wife watched a documentary called The Truth about Carbs and collared him. “She said: ‘You’ve got to do something about this.’” After carefully reviewing the academic literature – he is a scientist by training – Thomas went on a low-carbohydrate, low-calorie regime. (Like Thomas, type 2 diabetes sufferers can experience successful weight loss by severely restricting their carbohydrate intake.)

“The most surprising aspect of it all was that I wasn’t hungry at all,” Thomas says. He continued eating his usual diet of vegetarian curries, but gave up rice, bread and sweets. The weight melted off. Thomas sends me a graph tracking his blood sugar while on the diet – the line plummets vertically, like a bird falling out of the sky. His diabetes is now in remission. “It’s a huge weight off my mind,” he says.

Not everyone finds it so easy. Ultra-low-calorie diets are tough, particularly if you struggle to find time to cook. Emma wants to lose weight, but it just feels impossible. “I don’t have time to make healthy choices a lot of the time,” she says. “I have four children who won’t eat the same food, so I’m running around after them, and then I’m left to last, so I just grab a sandwich.”

She is not following a low-calorie regime, and worries about her long-term health. “When I go to bed at night, I think: ‘I must make this change tomorrow.’” She hopes to start the low-calorie diet when her youngest daughter starts nursery. “Then I can focus on me a bit more. Because one of my worst fears is having a leg amputated, or going blind.”

Perrin has been trying to stick to a low-calorie diet, but finds it hard to unlearn the eating habits of a lifetime. “I eat because of boredom,” Perrin says. “It gives you something to do when you’re watching the telly.” Quitting sugar floored her. “I felt awful.” She has, though, lost half a stone so far, and is hoping to send her diabetes into remission. “It’s been hard,” she says.

How to incentivise people to lose weight? “It’s about education,” says Riley. “Making sure people understand the risks, so they can take preventative steps like amending their diet and becoming more active, before it is too late.”

Riley welcomes the government’s commitment to halving childhood obesity by 2030, and is supportive of the sugar tax. But we need public-health interventions on a broader scale if we are to halt the diabetes epidemic. Lean calls for root-and-branch reform of our national eating habits. “We need to go back to how our parents and grandparents ate. Whole grains, pulses, vegetables – and meat for special occasions.”

Being fat is stigmatised – and type 2 diabetes sufferers are often unfairly judged. “To a certain extent, I’ve got the body I deserve,” says Perrin. “I’ve eaten a lot of crap over the years. But it isn’t purely self-inflicted.” Emma doesn’t tell most people about her diagnosis, because she finds it embarrassing. When she goes out for lunch with friends who know, she worries that they are watching what she eats.

“I think: ‘Are they going to judge me for my choices?’” Her mother berates her too. “She has all the time in the world to go to the gym,” Emma says.

The public-health messaging around type 2 diabetes is tricky – you don’t motivate people like Emma to make healthier choices by shaming them. But we must get it right because this is an unprecedented public-health emergency. Lean is hopeful that we will see the sort of radical consciousness-changing around obesity that we have witnessed with the climate emergency.

“Preventing diabetes must start among young people. We have Greta Thunberg out there showing that young people can grasp all sorts of things … We need to bring young people up to speed. Diabetes is a deadly, serious disease, and we all need to stop it.”

Thomas is evangelical about showing other people with diabetes that it can be reversed through diet. Unfortunately, he isn’t always successful – his mother and brother back home in Chennai are pre-diabetic, but won’t listen. “They think it’s too hard,” Thomas says. “They say: ‘You’ve got the will and determination, but we don’t.’”

Halliday is also spreading the message in between his packed schedule (the former agoraphobic is currently rehearsing for an am-dram production of The Addams Family). “I want to empower people to believe it can be done,” he says, “because I was a hermit living in my own home. If I can do it, anyone can.”

• This article was amended on 8 October 2019 to clarify the distinction between type 1 and type 2 diabetes. The former is an autoimmune condition. Type 1 is not associated with lifestyle, whereas type 2 is.