Fasting – Attack of the Dogma Clones
Many people fast these days for a variety of reasons. In my work, I have often had conversations about this with my clients. Of course, nobody believes me when I contextualise fasting - or any nutrition or training topic to be honest - and put it into perspective. After all, we all know a bit about nutrition and training and are therefore all experts in it ;)
Few will be able to argue with their mechanic or roofer because they've never built a car or roof... Wow... two paragraphs and I'm getting upset again. Back to fasting:
My client Zac recently asked me how I feel about fasting, whether I see any benefits for exercisers and whether a lifestyle change towards fasting is worth it. Here is my answer... as a director's cut (so very long).
I don't want to go into all the supposed promises of the fasting religion here. As always, I make no claim to completeness and offer here ‘only’ my take on things, which is in an attempt to provide an understanding of the science and applicability.
In this text you'll learn...
why fasting is a tool - but not a must,
why building muscle is more important than fasting in the long term,
that fasting is not a break, but an active state,
how fasting-like diets can work in everyday life,
why no diet is magical - it has to suit the individual.
What is fasting?
Fasting has deep roots in spiritual and cultural traditions. It was used for ‘purification’ and also as a cultural demarcation from other groups. In all four major world religions, for example, fasting takes place in preparation for a ritual event. Our hunter-gatherer ancestors often had to endure involuntary periods of fasting. Being able to fast was an evolutionary advantage. Greek philosophers saw it as a means of mental clarity and physical discipline. Stoics and ascetics used fasting as a path to inner freedom.
Today, fasting is often decoupled from spirituality and culture and is reinterpreted as a lifestyle or health strategy and... a substitute religion for some.
What do I think of (intermittent) fasting in general?
I think fasting is a good way to teach your system anti-fragility. Is fasting the super great tool to finally lose weight, live longer, work more focussed and finally achieve everything you set out to do? Answer: It depends. Basically the best answer for everything.
Everyone should be able to cope without food from time to time. The concept of ‘hangry’ is deeply fragile, if you ask me. For those of you readers who are less interested in pop culture (I got round the “you're too old to understand” part quite elegantly, didn't I?): Hangry, from ‘Hungry’ and ‘Angry’, means to be bad-tempered or irritable due to hunger. Hangry can be small children who have not yet learnt how their body works and are still learning to understand their emotions. As adults, surely we should have this under control?
Furthermore, I think that for most of us, fasting has no advantage over a calorie deficit without nutrient deprivation.
Is fasting useful and for whom?
Fasting has become a substitute religion for some (like almost every form of nutrition).
If you ask someone who is absolutely convinced of it, they will of course want to sell it to you. Mental focus, autophagy, longevity, curing cancer and whatnot are supposed to be benefits. In general, if someone tells you that XY cures cancer, you should always be careful. What cancer does it cure? There are countless types of cancer and they can all react differently to anything. The only people you should ask about this are your general practitioner and an oncologist (and no: Dr Google and ChatGPT are not among them).
Fasting and cancer:
Because we're on the subject... The big problem with cancer is that affected people literally disappear. Food intake can cause nausea and many have no appetite at all. If they are also fasting, they eat even less. That's not necessarily good! Here, by the way, I am a friend of meal replacment shakes.
Nevertheless, there is good evidence that fasting immediately around the therapy session can improve the outcome of chemotherapy in certain patients. But as I said, the only qualified person to talk to here is a doctor.
Fasting is the best way to lose weight!
- Your aunt at the family dinner, she read it on facebook.
Probably one of the greatest benefits of fasting is supposedly losing weight.
And indeed, many people will lose weight with fasting. It can be a great tool to reduce your weight. But the mechanism behind it is not some ancient secret that doctors and ... erm... the elites maybe?… don't want to tell you.
It's quite simple: you eat less. You are most likely in a calorie deficit when fasting. And if you don't stuff everything you avoid eating into another meal, you will lose weight. You might lose weight at first and then suddenly stop. You can read about one possible cause of this in my article on NEAT.
Does intermittent fasting increase focus?
People who skip breakfast, for example... scratch that, it's only ever people who boast about skipping breakfast ;) ... often report improved concentration in their work during the fasting period... i.e. until lunch. Such effects have even been demonstrated in animal and cell studies. I have no idea how this is measured. The animals probably filled out a questionnaire. In humans - as is so often the case - it is more complex. There are no clear, objective benefits for concentration, working memory or attention. In some studies, there were even slight losses.
However, many fasting people report increased alertness and less ‘brain fog’. Presumably due to a mixture of habituation, catecholamine peaks (please google it yourself) and the absence of constant snack stimuli.
My personal take on this is that we as a society have developed a distinct snacking culture and if I'm constantly eating, then of course it's going to be a distraction of some sort - on whatever level.
It's basically like I wrote at the beginning: We need to learn to be okay with feeling hungry again. But hey: that's just my opinion.
Do you live longer with fasting?
Fasting is also often used in the context of longevity. And yes, there is evidence that people who fast live longer. You can improve risk factors such as elevated blood sugar, chronic inflammatory processes, fat mass and your blood pressure. It also has positive effects on your cell repair. This process of autophagy is significantly increased during fasting. Fasting greatly reduces insulin and inhibits the mTOR signalling pathway. The mTOR signalling pathway controls cell growth, metabolism, protein synthesis and autophagy. In other words, mTOR is a kind of ‘switch-on button’ for growth, development and reproduction. It is active after training, for example, and is responsible for muscle growth.
Animal studies have shown that chronically increased mTOR activity due to excessive calorie intake, constant protein intake or chronically elevated inflammation levels is associated with a shortened lifespan. Although m-TOR inhibition leads to a longer lifespan in animals, it comes at the expense of muscle mass, reproductive capacity and regenerative ability. These animals suddenly started to spend all day on their mobile phones and wither away in their office chairs while constantly snacking. None of these animals had a gym or sports club membership.
This has not been clearly proven in humans because mTOR is also central to muscle development, bone health, wound healing and the immune system. Important: In humans, the mTOR signalling pathway is far more complex than in animals and we are still far from knowing everything about it in order to make reliable statements.
Ultimately, you can also achieve the same processes (on insulin sensitivity and autophagy) through a calorie deficit without nutrient deficiency. Fasting - and this is important to understand - is just a tool, a method to achieve a goal. But you can also achieve the same goal in other ways. If you find counting calories difficult or you can't control yourself, skipping meals may be the right way for you. And yes, it doesn't matter whether you skip breakfast, lunch or dinner. The fact that many people skip breakfast is more because it's the easiest to skip and they usually don't have time in the morning anyway... and because of fasting gurus who claim that breakfast is wrong.
And now take a quick look around you: the people around you, what do they need more of? Probably more muscle and less body fat, right? In my opinion, the decisive factor for longevity is not whether someone maximises their autophagy, but whether they have enough muscle mass. Because in the end (and yes, I do mean the end of life) the latter is more significant for health and ultimately a long health span. We're talking here about whether you can still do your shopping on your own at 80, open a bottle of water, get out of bed on your own... not whether you have big biceps or big bum muscles. Both can of course be a legitimate goal and are not in conflict with health.
What does this look like in practice? You should probably be in a calorie deficit from time to time without nutritional deficiencies. Eat nothing from time to time. Whether that's fasting days, intermittent fasting or simply eating less, it doesn't matter. You should also build muscle. I like the principle here
„You can train when you’re young, you should train when you’re middle-aged and you have to train when you’re old.“
Does fasting give the body a break?
My incredibly successful Instagram survey also revealed one interesting perspective on the question of why people fast - yes, exactly one perspective... unbelievably successful:
People want to ‘give the body a bit of a rest [with intermittent fasting]’.
An argument that is understandable at first. The need for rest or relief of the digestive tract or even a spiritual experience are behind it. Ultimately, however, it is biologically wrong. The body may not be digesting, but other energy-intensive processes are taking place instead. The body never takes a break, it is not an engine that needs a break to recover.
Nevertheless, (intermittent) fasting can make sense in the context of the constant availability of food.
However, the processes that come to the foreground during fasting require more adaptation and control than digestion. Fasting is therefore not a stand-by mode in which nothing happens and everything is at rest. On the contrary, it is hard work for the body. And with a healthy, balanced diet, the body will also get enough ‘digestive breaks’ between meals. Unless Snack is Life...
Proteins and fibre?
Another problem with fasting is that skipping a meal also means skipping nutrients that may be necessary. At a time when the US standard diet - or as I call it: Freedom-Diet - is seeing a gaining following, this can be an important factor (BAM! Two dad jokes in one sentence 💪). So most people will be eating even less protein and fibre.
Is it worth making a major lifestyle change for this?
Why are dietary changes such as fasting or veganism often accompanied by an improvement in health? It's not because one form of diet or another has magical healing powers. As a rule, people who eat vegan, for example, take a much closer look at what they eat. This alone can have a decisive influence on health. Followers of veganism eat significantly more fibre than those on other diets, which has a major impact on health! And by the way: it's clearly not down to not eating meat.
A lifestyle change to any diet is therefore always worthwhile if you can live healthier than you currently do. But the key question here is: do you really want to? Can you imagine living the rest of your life like this? If you can answer that with ‘yes’, then go for it.
How can fasting be optimally integrated into everyday life and training?
The answer to this is actually quite simple:
If intermittent fasting suits you, find a meal you want to skip and... skip it. See when you can train best in this context. Some people can train well on an empty stomach, others need a meal beforehand. It's very individual.
The same applies to other fasting models. However, I'd dare to say that you should significantly reduce your training intensity on complete fasting days.
Fasting without fasting - fasting mimicking diets
Fasting Mimicking Diets (FMD - a diet that simulates fasting) are a variant of fasting. FMDs were popularised by longevity researcher Valter Longo.
Longo's approach is simple:
You go on a severely calorie-restricted, plant-based diet over a five-day period, which is designed to trigger fasting effects in the body without having to completely abstain from food. Conveniently, Longo sells the whole thing as a ProLon 5-Day Fasting Box for €180.
Protein fasting or the green week
A teacher of mine takes a similar approach. Wolfgang Unsöld lets his customers complete his ‘green week’ from time to time. He calls it functional fasting. The basis is to eat steamed green vegetables and sufficient protein for 5-7 days. It's not about starving yourself. If you are hungry, you can eat vegetables or rice protein shakes.
This approach is particularly recommended as an introduction to dietary changes, during weight loss plateaus or as a short measure to set a ‘cut’. (Not to be confused with cut and bulk in bodybuilding, we don't do that kind of nonsense here ;) )
As it is also a severe calorie restriction (without a nutrient deficit!), I would argue that you can also get the effects of fasting with the ‘green week’ without actually fasting. The ‘green week’ is more socially acceptable than most fasting protocols and makes a lot more sense for people who exercise, as you don't have to give up important proteins... And it costs virtually nothing.
Conclusion
Apart from the fact that we all cannot do without certain essential macro and micronutrients, nutrition is very individual. One person will achieve personal peak performance and perhaps even enlightenment with fasting, the next is more successful with three meals. Others are better off eating a vegetarian diet... and still others only need sunlight... and eventually die after a short time.
People often fall in love with what they identify as ideal. Some of them see it as an opportunity to earn money. This is usually the moment when diets like fasting are turned into the holy grail for something and the wildest claims are made. With this in mind: If you need help with your diet or with the implementation of the ‘green week’, feel free to book a consultation with me ;)
There is no right or wrong here. The diet you choose should help you achieve your goals, be fun and - most importantly - fit in with your life.
Bonus points if you have to tell everyone you meet about it in the first 10 seconds.
Ciao
Marco
