Intermittent Fasting: What Exactly Is It?
Have you always been on the lookout for a diet that is both simple to follow and maintain, while also being healthy and delivering spectacular results? Perhaps 'Intermittent Fasting' is just what you need. Category and Product Manager Pepijn Aardewijn wanted to lose weight and delved into the fascinating world of fasting. He has since lost 20 kilograms! Below is his story, findings, and observations about this new diet craze that has flown over from America.
The last time I followed a strict diet was in preparation for the Seville Marathon. I had decided to finally run that marathon in under three hours again, and calculated that I would need to lose quite a bit of weight to achieve that. The Sonja Bakker diet was the diet of the moment, and several of my acquaintances had gone through her diet with good results. After three months, I was indeed significantly lighter. But it was not easy; simple and tasteless recipes, endless shopping lists, and I was constantly hungry. After the marathon, I also gained weight twice as fast and had no desire to consider dieting again. There had to be a healthier, easier way to achieve my goals. And there was, indeed: eating less…
Getting to Your Target Weight Faster
First, a bit of theory. If you want to lose weight, you need to eat less, preferably less than you burn daily. However, fat tissue requires less maintenance than muscle tissue, and muscles burn more than fat tissue during exercise. By doing extra endurance sports and simultaneously eating a calorie-restricted diet without increasing protein consumption, as with Sonja Bakker, you often burn a lot of muscle tissue in addition to fat tissue. And it is precisely those muscles that help you lose weight. The negative result is often only noticed after the diet: you gain weight faster than ever. A good diet should therefore meet a very important criterion: it must be so simple that you can always fall back on it when the scales demand it.
The diet must be so simple that you can always fall back on it when the scales demand it.
Is Not Eating Healthy?
Meet the latest diet trend: intermittent fasting! Regularly not eating. Could it be any simpler? Say goodbye to lists of do's and don'ts! Of course, the diet is not new or groundbreaking. We have been fasting for centuries, think of Ramadan or Carnival. Even the 'balance days' of the nutrition centre owe something to the theory behind 'fasting'. Real attention to intermittent fasting began a few years ago with Michael Mosley, a popular BBC presenter who likes to explore controversial topics (he once deliberately infected himself with tapeworm to document the effects). Mosley's book and TV documentary 'Eat, Fast & Live Longer', in which he explains the health effects of 'fasting', is considered the foundation of the now immensely popular 5:2 diet. There are now countless variations of this diet, all of which can be grouped under the name 'intermittent fasting'.
How It Works…
Although research into the effects of this new way of dieting has only just begun, there are already numerous variations and followers. Based on the limited research, no clear winner can be determined, but the principle is clear: you do not eat or eat very little for a certain period and regularly alternate this with periods in which you eat normally. A few commonly used variations are;
Alternate Day Version: in this hardcore version, periods of 24 hours of regular eating are alternated with periods of 24 hours of not eating, only drinking water, green tea, or coffee.
The 5:2 Diet:
Every week, you fast for 2 consecutive days. On fasting days, you can eat a very small amount, but the total calorie intake must not exceed 500 (women) or 600 (men) calories. These are not strict numbers; a bit more or less is allowed. During the other five days, you can eat whatever you want, as long as you do so in moderation.
Regular Fasting: here, you fast on several days a week, not necessarily consecutively. Calorie intake on these fasting days is very limited and often comes from 'green' smoothies.
Daily Fasting: You consume only one meal a day, or choose a fixed time slot of, for example, five hours in which you are allowed to eat (preferably between five and ten in the evening), and drink water and herbal tea for the rest of the day. Paleo experts believe that our distant ancestors hunted during the day and ate mainly in the evening. Such a system most closely matches the evolutionary dietary rhythm.
Theory and Research
From an evolutionary perspective, our bodies are already adapted to this. In prehistoric times, food was not abundant. Sometimes we had to travel for a few days or the daily hunt failed. Periods of not eating were common. A good paleo diet, therefore, fits a fasting regime and rhythm. Research is yet to really get going, but the initial indications are promising…
The Key Health Effects of Periodic Fasting
Antioxidants: Animals seem to be better able to withstand oxidative stress as a result of a fasting period. An effect that has also been demonstrated in human studies. During a fasting period, the body releases extra protective proteins, vitamins, and enzymes involved in combating free radicals. In this way, your body creates extra protection against oxidative stress and the resulting inflammation.
Fat Burning: Intermittent fasting promotes more efficient fat burning. Our current diet contains so many carbohydrates that we have trained ourselves to burn sugars. Run a half or full marathon, and you'll notice what happens when your body switches to the less efficient fat burning. Real sugar burners find it very difficult to lose fat tissue and hardly lose weight even with strict dieting. By fasting regularly, you train your body to burn fat again, as there is always plenty of it. This is also the basis of the previously popular sports fasting.
By fasting regularly, you train your body to burn fat again.
Insulin: Periodic fasting increases sensitivity to insulin. This is understandable, as the body gets used to occasionally receiving fewer sugars and carbohydrates. The importance of insulin, which helps with sugar transport, increases again. Science has also previously shown a strong link between insulin sensitivity and growth hormone production. With increased sensitivity to insulin, your growth hormone production will resume, especially if you also exercise more. Extra growth hormone and more exercise lead to better recovery and increased muscle growth. And it is precisely those muscles that are responsible for fat burning!
Cholesterol: Regular fasting is good for your cholesterol and triglyceride levels. Researchers have shown that your cholesterol balance improves with regular fasting. And this effect is measurable, even on days when you are not fasting and possibly consume unhealthy products that would not normally fit into a cholesterol-responsible diet.
Calories: There are even more spectacular health effects observed, but most of them are primarily in animals. Very interesting, of course, but for anyone looking to lose weight, the most obvious end conclusion and irrefutable observation is that fasting results in reduced calorie intake due to eating less.
Possible Disadvantages of a Fasting Diet
Hibernation
Classically trained dieticians like to point out the catabolic effect of fasting. By eating far fewer calories than you burn daily, your metabolism might slow down (the so-called hibernation effect). If you combine this with exercise, you would certainly burn muscles and thus gain weight faster after your diet. This might apply to a crash diet that lasts weeks or months, but the hibernation effect is demonstrably absent when the fasting period lasts less than 72 hours. The 5:2 diet, no matter how extreme it sounds, does not come close to that tipping point. Moreover, thanks to fasting, insulin sensitivity and growth hormone production increase again, which actually promotes muscle growth!
Extreme Binges
By not eating for two days, you might trigger extreme binges. Everyone reacts differently, and a little discipline is needed, even with this relatively easy-to-follow diet. Due to the increasing sensitivity of insulin, the body needs to produce less insulin. With lower insulin levels, the body becomes 'less deaf' to the other satiety hormone 'leptin'. Theoretically, the chance of binges should decrease rather than increase.
Sleep Problems
An underestimated problem with the fasting diet is your circadian clock. Evolutionarily, we are set to hunt during the day and eat in the evening. Our hormonal rhythm is therefore aligned with alternating eating and sleeping. Especially with fasting rhythms where you fast for 24 hours or longer, sleep problems can arise. In the 5:2 diet, you can solve this problem by consuming the calories you are allowed to have in the evening… However, with alternate day fasting, this problem can arise. People who experience sleep problems can consider using melatonin to support the day-night rhythm.
Evolutionarily, we are set to hunt during the day and eat in the evening.
Anti-Social
Perhaps one of the most challenging aspects of this diet is the social impact. Apart from the fact that mood, especially in the first few weeks, can suffer from hunger pangs. Meal times like breakfast, lunch, and dinner are part of a fixed social ritual. It remains difficult to sit down for lunch or dinner on your 'fasting days', or to have to cook for others. It takes a bit of resilience to just keep participating in those moments, with a glass of water. Moreover, with some fasting diets, you can still eat a little. For example, take an apple to lunch (80 kcal) or drink a broth (60 kcal).
In Practice
Interested? These are the results in practice. I have been following the 5:2 diet principle for three months now and combine it with extra exercise and a few dietary supplements that I have adopted from other diet regimes.
Which Diet?
On Mondays and Tuesdays, I eat nothing to almost nothing. I decided that the impact was least on those days. The first few times were quite tough, but nowadays I sometimes feel even better and fitter on fasting days than on the days after. A positive side effect that I cannot explain; I pay more attention to 'healthy eating', eat fewer carbohydrates, more proteins, spelt, and low GI products, and buy and cook with fresh, preferably organic vegetables.
Exercise and Fasting
Is actually a good combination! Although it may be that everyone reacts differently to it. The first half marathon is already on the calendar. I also consciously plan training sessions on Monday, Tuesday, and Wednesday morning. Precisely to train my body's fat burning again. Those 'fasted training sessions' are going easier than I thought. As an athlete, I was always very concerned about eating and the importance of sufficient energy during exercise. But training on an empty stomach is very trainable, and your body can adapt well to the situation. Especially Wednesday afternoon and Thursday, the days when I can eat again, seem harder. This may have to do with the recovery period. That is why I have chosen Thursday as a rest and recovery day.
Supplements
To prevent burning too much muscle as a result of endurance training on 'fasting days', I use a scoop of amino acids (BCAA) after training. Few kilocalories, but hopefully it prevents my muscles from being 'eaten' to recover. Additionally, I now use Resveratrol. Resveratrol is said to be involved in switching to more efficient fat burning under the influence of training during the fasting period. Especially in the first period, I used some magnesium and melatonin before going to bed. Nowadays, I no longer need that. I naturally use extra vitamin D, which helps maintain good resistance. Quite handy in winter.
Perseverance
Especially the first three weeks, the fasting period felt quite challenging. Compared to three months of starving with Sonja, those two days a week are quite manageable. By planning long training sessions in the evening, there wasn't much time left to brood over what I couldn't eat. After three to four weeks, everything settles in, and since then, it has been going reasonably easily for me.
The Scales
The scales don't lie. After 4 months, I am now down from 110 kilos to around 90 kilos. This means my BMI has dropped from 30.5 to 24.9. I am still losing weight each week and feel great about it. When I reach my target weight, I will adjust the schedule slightly. I hope I continue to feel just as good.
Author: Pepijn Aardewijn
