Intermittent Fasting: My 2-Year Review
Core - Edition Nº03
In 2016, on a warm sunny evening in London, I unknowingly broke my leg during a bike race due to a crash of more than 20 riders on the final straight.
When it happened, I woke up from what felt like a split-second moment of unconsciousness. I walked 150 metres to the race HQ and rested my leg on a table for an hour, expecting the pain and bleeding to subside eventually. And I did get to the hospital later that evening. After a daunting 2-hour wait, I got the inevitable confirmation that I punctured my fibula and needed surgery.
A few days later, I left the hospital, ready to begin a 10-week recovery period that would have me in a cast and unable to move too much. Although I could finally go home, this meant it was time for complete rest.
The mere thought of moping around doing nothing for weeks was already starting to drain me. So, I figured this was a perfect time to create some new habits. I started learning Spanish, did workouts to strengthen my other leg, and learned about intermittent fasting.
What Is Fasting?
Fasting is the period in which you’re not eating. It allows your body to digest food eaten earlier, process nutrients, and burn the excess to generate energy for your engine (vital organs and muscles).
Studies and articles describe fasting as beneficial to our body and mind. It can help lower inflammation, improve blood sugar, cholesterol and pressure, and help us lose weight—which most people want.
It sounds like a no-brainer.
Fasting has been around for as long as humans. But it was popularised in 2012 by Dr Michael Mosley’s documentary, Eat Fast, Live Longer and his book The Fast Diet, Kate Harrison’s book The 5:2 Diet, and Dr Jason Fung’s book The Obesity Code.
Dr Fung, in particular, uses a breadth of quality research and clinical experience to make it very clear that we should eat more fruits and vegetables, fibre, healthy protein and fats while avoiding sugar, refined grains and processed foods—and snacking! As he puts it: most nutritional “experts” inscribe the backwards approach as their recommendation—to eat more per day. Dr Fung points out that older societies coped well on carbohydrate-based diets, like the Irish with their potatoes, Asians with rice, and the French with bread. It’s startling how much obesity wasn’t a thing in the 1970s—not that long ago—and in fact, obesity cases were practically close to zero.
People were eating all kinds of sugary delights, not counting their calories (it was probably unheard of), not exercising much. They were eating as much carbohydrate as you could imagine—I’m talking 300 grams a day (compared to a “low carb diet” of 50 grams a day)—still, no obesity.
The answer: they didn’t eat all the time.
Intermittent Fasting (IF)
Fasting is the intentional abstinence from eating. Intermittent fasting is a systematic approach to your eating habits; it’s less about what you eat and all about when.
Mark Mattson, PhD, from John Hopkins School of Medicine, studied fasting for over 25 years and said that our bodies evolved to go long periods without food. Before humans learned to farm, they were hunter-gatherers who thrived without needing to eat for a while, as it took a long time to hunt and gather plant-based food.
Physiologically, we can live longer without food than water (not that we need to) which is why some people can fast for up to a month—for religious or personal reasons. Even half a century ago, as Christie Williams, a dietitian from John Hopkins, explains, it was easier to maintain a healthy weight in the past because people were more active and ate smaller food portions. There were no TVs or computers, and people mostly played outside and got more exercise.
As I mentioned, fasting is being in a state of not eating. Now, intermittent fasting refers to the scheduled approach of not being on and off with your regular eating periods. It’s a simplified way of eating the diet you need whilst allowing your body time to digest, process, and recover.
Intermittent fasting is not a diet. There are several ways to do it, but the premise stays the same: you set a consistent schedule of when to eat and when not to eat. There’s no need to count calories or be meticulous with exact portion sizes, especially initially.
What happens to you is that after a while without food, your body switches from burning sugar to fat, known as metabolic switching. Once your fatty acids start to mobilise, the goal becomes to preserve muscle mass and function whilst improving your overall weight.
Without sounding like some biohacker, I decided to give IF a try to help me stave off the typical recovery weight, increase my healthspan, and get better at burning fat during low-intensity activities (walking, slow cycling or daily chores and desk work).
The rules were simple: I’m only allowed to eat during a specific time. And to fast correctly, I can’t consume anything that may spark my metabolism. With IF, you fast for a particular number of hours (e.g. 16 hours or more) and then eat within an eight-hour window. This is called the 16:8 method, which is one of the most popular routines.
Fasting properly means you should avoid anything that may spark your metabolism. I initially messed this up as I added sweeteners to my morning black coffee. For most people, sticking to water is best.
In addition to being better at fat burning, I soon noticed improvements to my memory, heart health, performance and tissue health which are popular outcomes of regular fasting. But there’s one benefit that made me love this idea which you need to know.
According to a 2018 review, autophagy (“self-eating”) is the body’s way of “housekeeping”. It eliminates damaged organelles (“little organs” in our cells), long-lived misfolded proteins and invading pathogens and helps our body recycle building blocks and energy for “cellular renovation and homeostasis”.
Fasting enables the onset of autophagy which helps us handle various diseases, stress, cancers and infection. In other words, the body eats damaged cells and replenishes them with healthy cells. It’s a self-preservation method to recycle, repair and remove debris to help you think, move and live smoothly.
Though most studies on this were animal studies, there is evidence suggesting it helps us on a cellular level by:
Removing the toxic proteins associated with Parkinson’s and Alzheimer’s
Recycling residual proteins
Providing energy and building blocks for cells
Fasting and exercise work best at inducing autophagy. Still, with more attention from researchers, we will eventually understand much more about maximising the benefits from it on our health.
My Fasting Review
I’d never done intermittent fasting before, so I opted for a softer approach, to begin with. I followed a time-restricted process of 12 hours of fasting, which was easy when incorporated with my bedtime. So, I stopped eating at 9 pm and restarted at 9 am.
After a couple of weeks, I extended the fasting period to 16 hours. This was a lot harder initially as I was always comfortable with eating a lot in the morning. So I struggled, but luckily it got better after a few days. I drank more water (which was a bonus as I improved my hydration levels), and it helped me deal with the hunger pains that would eventually subside.
It took a few weeks before this became significantly easier. But when it did, this is what happened:
I had more energy in the day and no afternoon slump.
It took longer to feel tired.
I slept better.
I naturally drank more water per day (around four litres).
I felt more positive, creative, and open-minded.
Most changes were cognitive, which was as expected at the time. But because I felt more productive, I became more productive.
When my leg healed and the cast came off, I kept fasting to see any benefits to my training. I started with 30-minute and 60-minute easy spins on a turbo trainer. And just 2-3 weeks later, I was back on the road. My first ride was on a sunny weekend where I rode for 3 hours (50 miles) and immediately felt a difference.
I was already able to push harder up the hills and ride fast and with little fatigue. I noticed myself passing other riders on popular climbs and nearly forgot I was in a cast only a few weeks ago. And in fact, I was able to get back to proper training shortly after.
Why I Think It’s Unnecessary
Now you might be thinking, “What are you on about? You just explained how good it is!” And while fasting helped my broken leg recover faster and got me back to training earlier than expected, I still lost out on a few things.
When going back to my regular diet, I struggled to eat in the morning and eat enough when training; this hindered my performance and made things worse in the long term as it took a while to get used to eating normally again.
Fasting should do two things:
Fit seamlessly into your life
Help you during your routine
While it works well in many areas, it made things worse for me in the long term. So I reduced it for a few years until recently. Now, I still fast, but less frequently (such as on non-training days).
Many people will have far better results than me. But it’s also not something to recommend for certain people, such as children and teens, pregnant women, and people with diabetes or a history of eating disorders.
Fasting is a significant lifestyle change. You might be thinking, “That’s fine. I barely eat as it is, so fasting will be easy”, but fasting, and time-restricted eating, is not a place to limit your calories. You must still work to get enough of what you need—fasting helps you do so at the right time.
Intermittent fasting fits very well in most people’s lives , and it can make people’s schedules much smoother without having to worry about what you’ll eat all the time. Besides, the pros for most people vastly outweigh the cons.
However, if you’re very active, training or in a busy job, it’s going to be very hard to do intense work without food. You may feel fine during low-intensity work, but you can’t run on fat during everything you do (nor should you try).
The main thing is to do what makes you feel good and keep it consistent. That’s what health is all about.