It was July 15, 2012 – my 60th birthday – and time to take stock.

I considered myself pretty healthy, with no major medical issues to be concerned about. Five years earlier, I had nearly died from a blood clot to the lung (pulmonary embolus) and had to start taking a blood-thinning tablet, but I was on no other medications. I’d never smoked, didn’t drink much alcohol, exercised regularly (a mix of walking and the gym) and followed what I believed to be a healthy diet, low in fat and high in carbohydrate. Like a lot of people, I loved my pasta, rice, potatoes, and bread.

And yet despite following the dietary guidelines almost to the letter, I was overweight. In fact, according to the medical definition, I was bordering on obese. I’d probably put on 0.5 kilograms every year for the previous 30-odd years. As a result, by any reckoning, at 92 kilograms I was 10–15 kilograms over my ideal weight. My kids had started poking me in the belly and making cheeky comments about my ever-expanding abdomen.

Unfair, I thought. After all, I was doing ‘all the right things’. But in the back of my mind, I was also aware that my father had developed type 2 diabetes at 61 and that this horrible disease had led to significant complications that ultimately led to his death a couple of decades later. I didn’t want to go down that track.

Soon after that birthday, I read something from my old friend and colleague Professor Tim Noakes, who is generally considered to be the pre-eminent sports scientist in the world. Tim had started advocating a low-carb diet without the usual restrictions on fat. He was on this diet himself with dramatic results, and was encouraging others, including athletes, to adopt it too. So, when Tim Noakes comes out and states categorically that everything we believe about diet, obesity and heart disease is wrong, we all need to sit up and take notice.

But surely, I thought, the medical, nutrition and sports science community could not have been so far off the mark for all these years in advocating a diet low in saturated fat (to prevent heart disease) and high in complex carbohydrates (to fuel exercise). And yet that’s exactly what Noakes was saying. He even apologised for advocating a high-carb diet in his hugely popular book Lore of Running – no doubt he will change that for the next edition.

Tim’s conversion certainly got me thinking. I wanted to find out more.

My first step was reading Good Calories, Bad Calories, by award-winning journalist Gary Taubes. This book critically examines the history of the diet debate and looks not only at the science of diet, obesity, and heart disease, but also the politics, and how it came to be that governments as well as medical and scientific organisations came to recommend the low-fat, high-carbohydrate diet. For this book, Taubes spent four years analysing all the medical literature on the topic as well as speaking to all the major players in the field over the past 50 years. The result is quite amazing.

The wealth of positive evidence Taubes turned up shows that, contrary to what we’ve been led to believe, the traditional low-fat, low-calorie diet appears to be largely ineffectual, and in fact a diet low in carbohydrates aids weight loss and the reduction of various diseases. The key factor in controlling both blood sugar and blood fats (cholesterol and triglycerides), and ultimately hunger and weight, is insulin. But despite this evidence, as Taubes explains, the diet debate has been hijacked by the low-fat advocates – with subsequent disastrous consequences for our health. The epidemic of obesity is getting worse rather than better.

I began devouring books and scientific journal articles – anything I could get my hands on. I also became one of the nearly 7 million people to watch Robert Lustig’s classic YouTube video Sugar: The Bitter Truth. The more I read, listened, and watched, the more I became convinced that our current way of thinking about diet is wrong – but I was heartened to learn that there were lots of very insightful people out there who had challenged the dietary orthodoxies and were promoting a new way to eat. Welcome to the world of real food and low carb.

PUTTING IT INTO PRACTICE

Armed with this new understanding, I decided it was time to do an experiment in which I would drastically change the way I was eating. I eliminated nearly all carbohydrates from my diet and replaced them with healthy fats and proteins.

Before starting on my new diet, I took myself off for some blood tests and had my blood glucose, insulin, blood fats and liver function tested. I also recorded my weight. My blood test results weren’t too bad – or so I thought at the time – but in retrospect they showed that I was probably ‘pre-diabetic’ and on track to develop type 2 diabetes within a matter of years.

While my blood sugar was within normal limits, I had several other abnormalities that suggested I was heading down the same diabetic pathway as my father. My insulin level in particular was elevated, which was important given that insulin levels are now thought to be a more sensitive marker of impending diabetes than blood sugar levels. My blood fats were also slightly abnormal, with marginally elevated total cholesterol, slightly low HDL and markedly elevated triglyceride levels.

The blood test also confirmed that I had a condition known as fatty liver or, more precisely, non-alcoholic fatty liver disease (NAFLD). This had been noted on previous blood tests over the years, but I’d tended to ignore these results, probably because I didn’t really understand what they meant.

My rules were pretty simple, if quite dramatic compared to my old eating habits. There would be no more sugar or junk food, but more importantly no more rice, pasta, potatoes, bread, or cereal. There was no fruit juice, and the only fruits I would eat would be a few berries. Instead, I was going to have some of the things we’d been told for the past 30 years were bad for us: eggs and bacon, butter, cream, cheese, full-fat milk, grass-fed meat, cold-water fish (salmon and sardines), nuts and plenty of green vegetables. I wasn’t counting calories but was keeping a check on my total daily carbohydrate intake, aiming for a low intake of 30–50 grams, well down on my previous intake of more than 200 grams.

The first thing I noticed was that my appetite decreased dramatically. Previously, after my breakfast of cereal, I would be ravenously hungry by 11 a.m., hanging out for an excuse to eat lunch. Now, after a breakfast of eggs, bacon and maybe some avocado, I didn’t feel hungry at all, and most days didn’t even eat lunch. If I did get a little hungry during the day, I’d have some nuts (usually almonds) or a piece of cheese.

Then dinner was meat or fish with lots of non-starchy vegetables – such as broccoli, green beans, zucchini, Brussels sprouts, and cauliflower. Usually that was enough, but if I was still hungry, I’d have a bowl of berries – strawberries, raspberries, blueberries – with full-fat cream. Drinks were plenty of water, tea, or coffee (with a little full-fat milk) and the occasional glass of red wine.

I’d decided to weigh myself every Monday morning, and I consistently lost 0.5–1.5 kilogram each week. I was enjoying my food, feeling less hungry, sleeping better, and feeling more energetic – I was no longer drowsy in the afternoons, for example. Initially there was not much change in how I felt while exercising, but suddenly in week 6 I started to feel as if I could go forever. The hardest thing was nothing physical – it was getting my head around the fact that all these fats I’d been told for 30 years were bad for me were suddenly apparently okay.

There was one negative, though. I needed a new wardrobe. None of my clothes fitted. I went down two sizes in trousers and suddenly my jackets looked huge on me! But it was a small price to pay, I guess.

A WHOLE NEW LIFESTYLE

That was 10 years ago, and I’ve largely maintained that lifestyle ever since without difficulty. Once I got over the psychological barrier of ‘fat is bad’, I had no problems with the diet. I can still eat food that I enjoy: eggs with some combination of bacon, mushrooms, smoked salmon, or avocado, or my own ‘muesli’ of nuts and seeds with full-fat Greek yoghurt and berries for breakfast; cold meats, salads and cheese for lunch (if I have it at all); fish or meat for dinner with lots of vegies, followed by berries and cream for dessert. I drink water, green tea, coffee, bone broth and an occasional glass of red wine. My snacks have mainly been nuts (almonds) or cheese.

Over the past few years, I’ve talked to a lot of people about the benefits of these changes. Many of the conversations were initiated by people commenting on my weight loss or how healthy I look. I’ve had friends, colleagues and many of the athletes I’ve worked with make changes that have made a huge difference to their lives. A number of the elite athletes I look after have noted improvements in performance since changing their lifestyles.

For any way of eating to be sustainable, it needs to fit into a busy lifestyle, but I haven’t found my low-carb, healthy-fat diet difficult to maintain while travelling. And while at first glance many of these foods appear to be quite expensive, I’ll show you how it’s easy to eat both healthily and cheaply with a few tricks up your sleeve.