DR MICHAEL MOSLEY: Why the 5:2 diet reversed my diabetes

Actual scientific breakthroughs are incredibly rare, so I am privileged to have witnessed one first-hand, which I am sure will prove to be revolutionary

Actual scientific breakthroughs are incredibly rare, so I am privileged to have witnessed one first-hand, which I am sure will prove to be revolutionary

We often read about newly discovered ‘wonder’ drugs or ‘game-changing’ health technology. But in truth, few make an impact on the world.

Actual scientific breakthroughs are incredibly rare, so I am privileged to have witnessed one first-hand, which I am sure will prove to be revolutionary.

I am convinced that research by my friend Professor Roy Taylor and his colleagues from Newcastle University will change the way we treat the greatest health problem of our time – type 2 diabetes. These pioneering scientists have shown that this deadly condition, which affects about four million Britons, can be put into remission with a rapid weight-loss diet.

Now, in his new book, Life Without Diabetes, Prof Taylor reveals the science behind his discoveries and how you can do the same, at home.

In this week’s You magazine, you will find an unmissable taste of Prof Taylor’s simple, three-stage eating plan. There are more than 20 delicious, low-calorie recipes to make the diet far easier to swallow.

Before Prof Taylor’s discovery, it was thought that this pressing health problem – which affects twice as many people as it did 20 years ago – could not be reversed. It was a lifelong affliction and inevitably progressive. Complications include an increased risk of heart disease, dementia, amputation, blindness and kidney failure. People would be advised to take tablets and hope for the best. But thanks to a ground-breaking study, called DiRECT, carried out by Prof Taylor and his colleague Professor Mike Lean at the University of Glasgow, we now know this needn’t be the case.

I was so impressed by their research that I used it as inspiration, and adapted it slightly for my Eight-Week Blood Sugar Diet which involves eating 800 calories each day for 12 weeks. I am pleased to say it has so far helped thousands of readers send their diabetes into remission.

This approach is predicted to spark a seismic change in how doctors treat the condition, saving the NHS millions of pounds.

A recent study revealed that an 800-calorie diet could slash the annual cost of treatment for type 2 diabetes. Currently, treating each patient costs about £2,800 every year, which adds up to about ten per cent of the annual NHS budget. But diet interventions, such as the one pioneered by Prof Taylor, cost just over £1,000 per patient.

I’m keen to explain how I came to know Prof Taylor – both personally and professionally – and show you how, if you have raised blood sugars – and perhaps are on the verge of diabetes – you can bring them back down to normal with a rapid weight loss diet. I should know – I’ve been there…


My first meeting with Professor Taylor, in June 2014, followed my own battle with type 2 diabetes.

As I have written previously in this newspaper, I was diagnosed with the condition eight years ago, following a routine blood test.

My doctor said there was nothing that could be done apart from taking medication. I would start on the widely prescribed metformin, but there was a 50-50 chance that within a decade I would be forced to inject myself with insulin. Naturally, I was shocked.

My father had developed type 2 diabetes in his late 50s, and despite being on medication, he died of complications of that disease, including heart failure. I didn’t want to follow his example, so I looked elsewhere for answers.


Nearly four million Britons have type 2 diabetes, but it is still a hidden disease.

One in four people in the UK who have it, don’t know it yet and they sometimes won’t find out until they have an NHS over-40s screening. About one in three adults have prediabetes, where blood sugars are abnormally high but not yet in the diabetic range.

With prediabetes there are no symptoms – it is usually picked up by a random blood test. Unless it is dealt with, many will go on to develop diabetes, but if you lose weight, particularly around the gut, you massively reduce the risk.

Prof Taylor’s three-stage diet (on Pages 31 to 46 of You magazine) might just help…

I soon came across research showing the benefits of something, which was little-known at the time, called intermittent fasting. It involved restricting calories for a portion of the week, and led to my discovery of a new approach to weight loss which I called the 5:2. For those of you who aren’t familiar with it, it involves cutting calories for just two days each week.

Over the course of two months, I lost nearly a stone and a half – and my blood sugar levels returned to normal, where they have stayed ever since. This proved to be the inspiration for my first international bestseller, The Fast Diet, with journalist Mimi Spencer.

Despite this success, I still didn’t fully understand the science behind my health transformation. Then I read about the work of Prof Taylor. It made a lot of sense, so I took a train to his research centre at Newcastle University to find out more.

He explained that the reason I had developed the condition in the first place was because I had, over the years, accumulated too much fat around my gut. This fat had begun to clog up my liver and pancreas, stopping them working properly. These organs are vitally important for regulating blood sugar levels. In type 2 diabetes, the body’s system of regulating blood sugar goes awry.

Prof Taylor, who is an honorary endocrinology consultant at the Newcastle Hospitals NHS Trust, also introduced me to something he called ‘the personal fat threshold’. This is partly why some people can become hugely overweight without developing diabetes, while others can be a healthy weight and still become diabetic.

Your personal fat threshold is determined largely by your genes – having a close relative with diabetes, like I did, puts you at much greater risk.

But there was good news. He had conducted studies which found that most people could return their blood sugars to non-diabetic levels by losing just one gram of fat from around their pancreas. To do that, they needed to lose roughly ten per cent of their body weight. Then Prof Taylor told me about an upcoming trial called DiRECT – which would prove to be hugely important.


Along with Mike Lean, professor of human nutrition at Glasgow Royal Infirmary, and supported by a multi-million-pound grant from charity Diabetes UK, Prof Taylor recruited nearly 300 type 2 diabetes patients.

Half were asked to follow a rapid weight-loss approach to treatment, and the other half allocated standard NHS care. Patients in the weight-loss group were given a strict 800-calorie- a-day eating plan for up to 12 weeks, made up of three meal-replacement shakes.

The initial findings, published at the end of 2018, were sensational. Those eating 800 calories a day for 12 weeks lost an average of one-and-a-half stone – and the weight stayed off for more than a year.


I am not the only Mosley to have been inspired by Prof Taylor’s work. My middle son Jack, who is now a doctor at the Royal Preston Hospital in Lancashire, was so interested in the professor’s work that he decided to do a research project where he would try to identify why some DiRECT participants could keep the weight off long-term, while others couldn’t.

Supervised by Prof Taylor himself, Jack conducted numerous interviews with people who had completed the diet.

Their answers were fascinating.

Pride in overcoming the disease, boosting mood with regular exercise and enjoyment in buying new, smaller clothes were all effective motivational drivers.

Close bond: Dr Michael Mosley pictured with his sons, from left, Alex, Jack and Dan

Close bond: Dr Michael Mosley pictured with his sons, from left, Alex, Jack and Dan

Close bond: Dr Michael Mosley pictured with his sons, from left, Alex, Jack and Dan

But one of the most important factors when it came to maintaining weight loss was support from family and friends.

All participants faced emotional challenges at some point – injury, family tragedy or the loss of a job, for example.

Going through a low patch often led to comfort eating.

The main difference between unsuccessful and successful dieters was that while the former bounced back, the latter did not.

And those who were the most successful were the participants with greatest support from family and friends.

Having someone to spur them on through difficult times was key. 

In comparison, the control group lost an average of just over 2 lb. What’s more, half of the 800-calorie patients put their diabetes into remission. Their blood sugar levels went back to normal, without medication. Only four per cent in the control group managed to achieve this.

A follow-up study, was published last year and, impressively, the 800-calorie group had managed to keep most of the weight off.

Despite being on much less medication, they also continued to have lower blood sugar, cholesterol and blood pressure levels than the control group.

In the group getting standard NHS care, two had suffered strokes, one had an amputation, and another sadly died from complications of the disease.

Other research has trialled different versions, for example swapping some of the calories in shakes for a small portion of vegetables to increase bowel-friendly fibre.

The results of the DiRECT trial were so promising, that NHS chiefs have announced that more than 5,000 patients are being offered a rapid weight-loss programme, starting in April.

We used to be told: Take pills and hope for the best. One man has changed all that

We used to be told: Take pills and hope for the best. One man has changed all that

We used to be told: Take pills and hope for the best. One man has changed all that

As Prof Lean said to me: ‘For years we’ve been telling type 2 diabetes patients to take the pills and not worry too much.

‘It is time to tell them that this is a serious disease with nasty complications, particularly if you develop it in your 40s or 50s. But the good news is that with the right help, many people can now get shot of it.’


Another bit of good news is you don’t have to be part of a medical trial to see these phenomenal results – thousands of people have had great success sticking to this sort of programme.

Of course if you’re doing it at home, the circumstances will be different. For instance, in the DiRECT study, patients were asked to consume special meal-replacement shakes. These shakes can be very helpful, particularly when starting out. But you can also do it with real, solid food.

A small study conducted by researchers at Oxford University randomly allocated 33 overweight patients with type 2 diabetes to an 800-calorie-a-day diet, or standard care.

Patients were given advice from health professionals – including ideas for recipes – and prepared meals for themselves at home.

After three months, those on the 800-calorie diet lost an average of one-and-a-half stone and saw big drops in their blood sugar levels.

As in the DiRECT study, many of them were able to come off their medication.

There’s plenty more recipes that stick within the 800 daily calorie limit on my website, thefast800.com.

But what if a rapid weight- loss diet isn’t for you? Any diet that involves losing enough weight to unclog your pancreas will almost certainly help. ‘Enough’ usually means ten per cent of your body weight – or at least 22 lb if you are overweight.

One tried and tested method of losing weight at a slower pace is via the 5:2 diet, which is the way I did it.

For five days of the week, eat a healthy, balanced diet, and steer clear of sweet, fatty stuffs such as chocolate and crisps. Then, for two days, stick to 800 calories.

In a recent Australian study involving 137 patients with type 2 diabetes, those allocated to a 5:2 diet managed to sustain an average weight loss of roughly a stone over the course of a year, leading to big improvements in blood sugar levels. The participants who were the most diligent kept off an average of 1st 9 lb.

In Prof Taylor’s three-stage plan in You magazine, he recommends sticking to three, small and healthy meals daily for long-term weight maintenance, and 100 calories of vegetables for added fibre. The specially crafted recipes include imaginative things you can do with vegetables, which will help the process.

These days, he recommends a total limit of a slightly stricter 700 calories, to allow room for the odd cup of tea – which we know Britons struggle to live without.

If you can manage this, great. But many struggle with this, knowing that they’ll be tempted by the occasional weekend takeaway or chocolate bar.

So some people find a 5:2 eating pattern easier to stick to, as it leaves space for the odd treat. Just make sure it really is occasional, of course.

Life Without Diabetes, by Professor Roy Taylor, is published by Short Books, priced £9.99.