The Fast Diet: The secret of intermittent fasting � lose weight, stay healthy, live longer

 

 

O
ver the last few decades, food fads have come and gone, but the standard medical advice on what constitutes a healthy lifestyle has stayed much the same: eat low-fat foods, exercise more… and never, ever skip meals. Over that same period, levels of obesity worldwide have soared.

So is there a different, evidence-based approach? One that relies on science, not opinion? Well, we think there is. Intermittent Fasting.

When we first read about the alleged benefits of Intermittent Fasting, we, like many, were sceptical. Fasting seemed drastic, difficult – and we both knew that dieting, of any description, is generally doomed to fail. But now that we’ve looked at it in depth and tried it ourselves, we are convinced of its remarkable potential. As one of the medical experts interviewed for this book puts it: ‘There is nothing else you can do to your body that is as powerful as fasting.’

Fasting is nothing new. As we’ll discover in the next chapter, your body is designed to fast. We evolved at a time when food was scarce; we are the product of millennia of feast and famine. The reason we respond so well to Intermittent Fasting is that it mimics, far more accurately than three meals a day, the environment in which modern humans were shaped.

Fasting, of course, remains an article of faith for many. The fasts of Lent, Yom Kippur and Ramadan are just some of the better-known examples. Greek Orthodox Christians are encouraged to fast for 180 days of the year (according to Saint Nikolai of Zicha, ‘Gluttony makes a man gloomy and fearful, but fasting makes him joyful and courageous’), while Buddhist monks fast on the new moon and full moon of each lunar month.

Many more of us, however, seem to be eating most of the time. We’re rarely ever hungry. But we are dissatisfied. With our weight, our bodies, our health.

Intermittent Fasting can put us back in touch with our human selves. It is a route not only to weight loss, but also to long-term health and wellbeing. Scientists are only just beginning to discover and prove how powerful a tool it can be.

This book is a product of that cutting-edge research and its impact on our current thinking about weight loss, disease resistance and longevity. But it is also the
result of our personal experience. Both are relevant here – the lab and the lifestyle – so we investigate Intermittent Fasting from two complementary perspectives. First, Michael, who used his body and medical training to test its potential, explains the scientific foundations of Intermittent Fasting and the 5:2 diet – something he brought to the world’s attention last summer.

Then Mimi offers a practical guide on how to do it safely, effectively and in a sustainable way, a way that will fit easily into your normal, everyday life. She looks in detail at how fasting feels, what you can expect from day to day, what to eat and when to eat – and provides a host of tips and strategies to help you gain the greatest benefit from the diet’s simple precepts.

As you’ll see below, the Fast Diet has changed both of our lives. We hope it will do the same for you.

I am a 55-year-old male and before I embarked on my exploration of Intermittent Fasting I was mildly overweight: at 5’11”, I weighed around 85kg (13 stone 6lb) and had a Body Mass Index ((BMI) of 26, which put me into the overweight category. Until my mid-30s, I had been slim, but like many people I then gradually put on weight, around 0.5kg a year. This doesn’t sound much, but over a couple of decades it pushed me up and up.
Slowly I realised that I was starting to resemble my father, a man who struggled with his weight all his life and died in his early 70s of complications associated with diabetes. At his funeral many of his friends commented on how like him I had become.

I was fortunate enough, while making a documentary for the BBC, to have an MRI scan done. This revealed that I am a TOFI, Thin on the Outside and Fat Inside. This is the most dangerous sort of fat, visceral fat, because it wraps itself around your internal organs and puts you at risk of heart disease and diabetes. I later had blood tests that showed I was heading towards diabetes, with a cholesterol score that was also way too high. Clearly I was going to have to do something about this. I tried following standard advice. Except it made little difference. My weight and blood profile remained stuck in the ‘danger ahead’ zone.

I had never tried dieting before because I’d never found a diet that I thought would work. I watched my father try every form of diet, from Scarsdale through Atkins, from the Cambridge Diet to the Drinking Man’s Diet. He lost weight on each one of them, and then within a few months put it all back on, and more.

Then, at the beginning of 2012, I was approached by Aidan Laverty, editor of the BBC science series
Horizon
, who asked if I would like to put myself forward as a guinea pig to explore the science behind life extension. I wasn’t sure what we would find, but, along with producer Kate
Dart and researcher Roshan Samarasinghe, we quickly focused on calorie restriction and fasting as a fruitful area to explore.

Calorie restriction (CR) is pretty brutal; it involves eating an awful lot less than a normal person would expect to eat, and doing so every day of your – hopefully – long life The reason people put themselves through this is that it is the only intervention that has been shown to extend lifespan, at least in animals. There are around 50,000 CHRONies (Calorie Restrictors on Optimal Nutrition) worldwide, and I have met quite a number of them. Despite their generally fabulous biochemical profile, I have never been seriously tempted to join their skinny ranks. I simply don’t have the will-power or desire to live permanently on an extreme low-calorie diet.

So I was delighted to discover Intermittent Fasting (IF), which involves eating fewer calories, but only some of the time. If the science was right, it offered the benefits of CR, but without the pain.

I set off around the US, meeting leading scientists who generously shared their research and ideas with me. It became clear that IF was no fad. But it wouldn’t be as easy as I’d originally hoped. As you’ll see later in the book, there are many different forms of Intermittent Fasting. Some involve eating nothing for 24 hours or longer. Others involve a single, low-calorie meal once a day, every other day. I tried both but couldn’t imagine doing either on a regular basis. I found it was simply too hard.

Instead I decided to create and test my own, modified version. Five days a week, I would eat normally; on the remaining two I would eat a quarter of my usual calorie intake (i.e. 600 calories).

I split the 600 calories in two – around 250 calories for breakfast and 350 calories for supper – effectively fasting for 12 hours at a stretch. I also decided to split my fasting days: I would fast on Mondays and Thursdays. I became my own experiment.

The programme,
Eat, Fast, Live Longer,
which detailed my adventures with what we were now calling the 5:2 diet, went out on the BBC during the London Olympics in August 2012. I expected it to be lost in the media frenzy that surrounded the Games, but instead it generated a frenzy of its own. The programme was watched by over 2.5 million people – a huge audience for
Horizon
– and hundreds of thousands more on YouTube. My Twitter account, @DrMichaelMosley, went into overdrive, my followers tripled; everyone wanted to try my version of Intermittent Fasting and they were all asking me what they should do.

The newspapers took up the story. Articles appeared in
The Times, The Daily Telegraph, The Daily Mail
and
The Mail on Sunday
. Before long, it was picked up by newspapers all over the world – in New York, Los Angeles, Paris, Madrid, Montreal, Islamabad and Delhi. Online groups were created, menus and experiences swapped, chat rooms started buzzing about fasting.

People began to stop me on the street and tell me how well they were doing on the 5:2 diet. They also emailed details of their experiences. Among those emails, a surprisingly large number were from doctors. Like me, they had initially been sceptical, but they had tried it for themselves, found that it worked and had begun suggesting it to their patients. They wanted information, menus, details of the scientific research to scrutinise. They wanted me to write a book. I hedged, procrastinated, then finally found a collaborator, Mimi Spencer, whom I liked and trusted and who has an in-depth knowledge of food. Which is how what you are reading came about.

I trained as a doctor at the Royal Free Hospital in London and after qualifying joined the BBC as a trainee assistant producer. Over the last 25 years I have made numerous science and history documentaries for the BBC, first behind the camera, more recently as a presenter. I was executive producer of
QED, Trust Me I’m a Doctor
and
Superhuman
. I worked with John Cleese, Jeremy Clarkson, Professor Robert Winston, Sir David Attenborough and Professor Alice Roberts. I devised and executive-produced three of the most popular science or history programmes of the last decade:
Pompeii – the last day, Supervolcano
and
Krakatoa
.

As a presenter I have made a dozen series for the BBC, including
Medical Mavericks, Blood and Guts, Inside Michael Mosley, Science Story, The Young Ones, Inside the Human Body
and
The Truth about Exercise
. I am currently making three new series, as well as being a regular science presenter for the BBC’s
One Show.

I have won numerous awards, including being named Medical Journalist of the Year by the British Medical Association.

I started Intermittent Fasting on the day I was commissioned to write a feature for
The Times
about Michael’s
Horizon
programme. It was the first I’d heard of Intermittent Fasting, and the idea appealed immediately, even to a cynical soul who has spent two decades examining the curious acrobatics of the fashion industry, the beauty business and the diet trade.

I’d dabbled in diets before – show me a 40-something woman who hasn’t – losing weight, then losing faith within weeks and piling it all back on. Though never overweight, I’d long been interested in dropping that reluctant half a stone or more – the pounds I picked up in pregnancy and somehow never lost. The diets I tried were always too hard to follow, too complicated to implement, too boring, too tough, too single-strand, too
invasive, sucking the juice out of life and leaving you with the scraps. There was nothing I found that I could adopt and thread into the context of my life – as a mother, a working woman, a wife.