Let’s be honest, the first time we hear about fasting, it’s FEAR! And yet, when we start to take an interest in ketogenic food, we see it coming from everywhere! We hear intermittent fasting, OMAD, 16: 8, among others. Little by little we are overwhelmed by the sad impression that we need a doctorate to be able to understand all that. And as if it was not complicated enough we can remember all that we have heard so far: “Breakfast is the most important meal of the day”, “you must never skip a meal we will starve and eat 25 times more at the next meal “, etc, etc … The (very) complete guide to intermittent fasting
We went through all these stages, it was neither easy nor clear nor obvious. So as we are nice ( 😉), we will try to make things simpler on the subject. So you can, if you wish, approach the experience in the most complete relaxations. That’s great, stress is one of the biggest enemies of weight loss . The intermittent fasting, one of his greatest allies. So let’s start at the beginning.
Summary : Guide to Intermittent Fasting
- Intermittent fasting, what is it?
- Fasting is in our genes
- How long do I do this?
- Here is a “small” list of identified benefits:
- Practical interests of intermittent fasting
- Why intermittent fasting and ketogenic nutrition are the best friends in the world ?
- What can be consumed during intermittent fasting?
- Other questions / comments that often come up about intermittent fasting
- Are there any contraindications?
Intermittent fasting, what is it?
On this point, the name is rather explanatory in the end. Guide to Intermittent fasting is voluntary abstinence from eating for a limited period of time. We all do it already a little, thanks to sleep. If I’m done eating at 9pm, going to bed, I sleep, and then I have breakfast at 7:30, I’ve just done 10:30 intermittent fasting! Easy !
In practice, we will still try to aim for periods a little longer than that. Otherwise it would not be worth talking about it . The goal is to reproduce the food rhythms for which the human being has evolved.
Indeed, today it seems normal and obvious to do three to five meals a day (with snacks), we must understand that, from a historical point of view, we are living a wonderful time, but also deeply abnormal.
Fasting is in our genes
The human being, during the vast majority of his evolution (which goes back about 2 and a half million years), lived by eating WHEN he COULD. It was sometimes two meals a day, often one, sometimes less. While we modern humans, if we ate every time we could, we would eat all the time! And for many of us, that’s exactly what we do: p .
With intermittent fasting, we try to find our natural feeding cycle, the one for which we are adapted, the one for which we have evolved. You will see that there is ONE PACK of science to support the fact that it is ideal for us. But then, if my little fast / dodo of 10:30 is not enough …
How long do I do this?
Some fasting methods have been implemented for health programs, bodybuilding and weight loss.
However, there are no “rules” per se on fasting times. The only thing to know is that the benefits begin to be visible from 12 hours of fasting. Moreover, this is what our grandparents usually did (from 7pm to 7am) and oddly obesity was still very rare at the time!
Unfortunately, this is not necessarily enough to improve insulin resistance (you are told a little more later in the article ). Then, free to decide how long you want to do in addition to 12h basic. Some people will fast 14 hours each day, others 27 hours once a week, and still others will grow up to several months ( The fasts of several months are generally practiced by people very closely monitored from one point. from a medical point of view, do not do this alone with you children! ).
Nevertheless, for those who prefer, there is a jargon that is often used by the fasters. So we will explain to you what each of the terms that you may have already seen if you are interested in a little fasting
The intermittent fasting “classic”, called 16: 8 or sometimes “Fasting”
The 16: 8 is called this because it consists of fasting for 16 hours in a row and eating in a time slot of 8 hours. In fact, this method of fasting has been brought up to date by a bodybuilder Martin Berkhan. The latter created the LeanGains method of exercising during intermittent fasting and then feeding after exercise.
One study showed that 16-hour fasting among bodybuilding practitioners resulted in an identical gain in muscle mass, and a higher fat loss than those who did not fast, with equal daily calories and macros. In practice, how do we do it? We (and certainly many other people who do intermittent fasting), what we do most often is to fast after dinner from 20h then eat our meals between 12h and 20h. The fact of keeping the lunch and the dinner allows us to have more easily a social life (to us brunch and drinks!) And thus to make simpler its daily setting up. Guide to Intermittent Fasting
This is the one we recommend the most because in our opinion it has the best accessibility-benefit ratio.
The 20: 4 or the “Warrior diet”
If you understand how the 16: 8 works, you should have guessed how the 20: 4 works! It’s intermittent fasting for warriors! And yes, this time, we fast for 20 hours and eat in a window of 4 hours.
The “Warrior Diet” is a book written by Ori Hofmekkler. This is one of the first to appear as a diet that incorporates intermittent fasting. The principle is based on the importance of the composition of meals and the time devoted to them.
For example, you can have a snack from 18h and dinner until 22h and then fast until 18h the next day
One meal a day, or “OMAD” (One Meal A Day)
Because OMAD is still easier to pronounce than URPJ (you can try at home if no one is watching )
This configuration is simpler than the other two. It consists of taking, as its name suggests, only one meal in the day at the same time. Very handy when you want to save time and we like to make huge meals!
If you want to know more about the why and how of the OMAD, we really like this video from the YouTube channel “What I’ve Learned” (What I learned). The video is in English but you can activate French subtitles on it. If you like our articles, then you will LOVE these videos.
The 5: 2, or “Eat Stop Eat”
This is the type of fast that has been the most studied experimentally for the treatment of obesity.
Here, the numbers 5: 2 do not relate to the number of hours but the number of days of the week. In concrete terms, this means eating for 5 days and fasting for 2 days. The fasting conditions are a little different for the 5: 2. Indeed, during the 2 days of fasting, studies have shown that beneficial effects on weight loss were visible as long as one consumes no more than 500 calories on each of the 2 days. So, it is possible to eat a snack if you feel the need as long as it does not exceed 500 calories.
Okay, we’re a little clearer about the jargon now. But all this does not yet answer the most important question: “Why should I go to inflict this on myself?” Guide to Intermittent Fasting
Here is a “small” list of identified benefits:
Decreases insulin levels , blood glucose
When we eat, we make insulin through our pancreas to allow glucose to enter our cells and be used for the functioning of our body. The more we eat and the more we produce insulin. However, if this “machine” is not often left to rest, one can develop insulin resistance and develop metabolic diseases such as obesity, diabetes, Ahlzeimer..
The best cure for pausing the insulin “machine” is of course fasting! Indeed, when we fast, our insulin level will drop until all the excess blood glucose is used. To learn more about the benefits of lowering insulin levels, we invite you to read this article “the keto for beginners” Guide to Intermittent Fasting
Accelerates weight loss and fat burning
A cross-analysis of studies shows that by removing breakfast, people eat less and lose more weight. As we eat in a smaller window, we eat less! If you consider that you made an OMAD, do you imagine eating 3 meals in an hour?
In addition, thanks to a low insulin level , the body will then be able to use stored fat to produce energy (as you read in this article for beginners)
Used to improve its energy
Once we have used our entire store of glycogen (stored energy from carbohydrates), our body starts to use a much more stable source of energy : our fat.
This way, we avoid diet drops and our energy is constant throughout our fast.
Improves the activity of our brain
Fasting would activate a protein responsible for learning and memory, the BDNF or brain-derived neurotrophic factor . Thanks to it, our neuronal connections are faster and more efficient
Improves mental clarity and concentration
Fat is the best source of energy for our brain. When the latter finally has access to this fuel, it’s the happiest! It can then work faster and better focus.
Stimulates autophagy
Another bizarre term. Autophagy means to eat oneself. Even if it does not look, it’s a good thing, believe us! We also talk about cellular cleaning. The cell will self-regulate, retrain, to protect our body. In a few words, this is a mechanism that will allow the renewal of our cells. It’s a natural process, but it’s even better when you’re fasting.
Decreases oxidative stress and inflammation
By fasting, our body develops resistance to oxidative stress and regulates the rate of free radicals responsible for the aging of our cells.
It will also be able to stimulate anti-inflammatory pathways while reducing pro-inflammatory elements. In short, more anti, less pro, it’s less chronic inflammation in our body, and that’s good!
Would participate in our longevity
If you want to learn more about the benefits of fasting, we recommend the book of a doctor well known in the field, Jason Fung. He believes that fasting should be practiced by all who wish to lose weight and be in good health: The Complete Guide to Fasting
Practical interests of intermittent fasting
It’s free !
The cheapest meal in the world is the NON meal As we skip one to several meals, we save money on the shopping budget! In a consumer society that always pushes us to consume more, to take more products, to be interested in the last “superfood”, it’s refreshing to know that we can bring REAL benefits to its health not in taking something extra, but making meals in LESS.
In addition, as we do less meals, it becomes easier to afford products of better quality. It brings a little more to his health (and his pleasure too)!
It’s super simple!
Unlike other food with rules more or less clear and more or less defined (and, yes, the keto also comes in this case: p), intermittent fasting is still super simple: either it is time to eat, it’s time to NOT eat. No possible negotiations with oneself, no hard rules to interpret.
We save time!
Since we have fewer meals to prepare, we spend less time thinking about our menus and cooking. Results, we gain a lot of time to do something else! You can enjoy more of your family, watch the movie you wanted to see for a long time, train you on a new skill … In short, so much more time for you that you will not know what to do with your life at first! It is disturbing, but we quickly taste. We feel so much more free and serene. Guide to Intermittent Fasting
Why intermittent fasting and ketogenic nutrition are the best friends in the world ?
So far, you have been told about fasting independently of ketogenic nutrition. For the excellent reason that both practices are not necessarily related. Intermittent fasting will be excellent for you even if you do not eat keto. The ketogenic diet will keep all its benefits even without intermittent fasting.
However, if you return to look at the list of benefits of fasting, you will certainly notice that it looks VERY strongly to the benefits associated with ketogenic nutrition. And this is NORMAL, since both influence the same hormonal mechanisms, starting with the regulation of insulin .
Moreover, when we come from the ketogenic diet, it gives us a lot of small advantages on the subject, to make the transition to intermittent fasting even sweeter:
Satiety has usually been improved, which will make it easier to skip one or more meals. (By the way, many ketogenic food practitioners come to intermittent fasting naturally, without even knowing what it is, just because the urge to eat is no longer so present).
Our body has already adapted to using its fat as a source of energy, which allows us to have better response and better energy at the beginning. Guide to Intermittent Fasting
But for all that, we can start intermittent fast even without eating keto, we would even tend to say MORE if we do not eat keto. By the way, that’s what François did, he practiced intermittent fasting a few months before starting the keto, and that’s overall pretty good
What is the right moment?
The right time to fast is yours. It’s up to you alone to decide if you feel able to fast. The right moment depends on thousands of factors that will allow you to feel good (or not) to do it: your motivation, your health, your stress level, your schedule.
Be kind to yourself and choose to fast because you want to. If you force yourself when you are not ready to do so, you may have a bad experience. This type of stress is not good for your health!
What can be consumed during intermittent fasting?
At first sight this question may seem illogical: if I fast, I consume nothing? Yet in practice, there may be small variants. It will depend on the results one is looking for, and the expectations one has for fasting. Ideally, you can consume water, tea and coffee. That’s what will get all the benefits that we talked about.
If you’re only aiming for cell regeneration, insulin sensitivity, or better mental abilities, you can afford a little bit of fat, like fatty coffee or bone broth. Fat will not increase your insulin levels, and your glucagon level, responsible for autophagy and ketosis.
On the other hand, if the main objective is to lose weight, the best thing is to stay in water and infusions. Fasting will help to act on the two factors of weight gain: on the one hand it will regulate the hormonal functioning, and on the other hand it will limit its energy intake.
Although the ketogenic diet improves the metabolism, it is not magical and it is perfectly possible to eat enough not to lose weight, see to take it. By staying strict on your fast, not only do you have the best way to get all the benefits, but you also reduce the chances of eating “too much”. Guide to Intermittent Fasting
But you must also be pragmatic: if a fatty coffee or broth prevents you from throwing yourself on a slice of keto cheesecake, obviously it’s better! As said above, you will still retain the majority of the benefits.
I count my macros: I have to keep the same?
On this subject, the main thing to remember is: do you trust . Of course, fasting will not give you the right to increase your macros. However, apart from perhaps for your proteins , do not see your macros as a goal to achieve. Listen to yourself, and if you are no longer hungry and you feel good, do not force yourself.
A simple exercise to get started: Practice skipping a meal
Who has never heard this phrase: “Breakfast is the most important meal of the day!”? It is transmitted from generation to generation, and it continues to persist in beliefs. Some even force them to eat because they think that if they skip a meal, they may not have enough energy for the morning and / or gain weight. Yet this belief is actually based on studies funded by Kellogg’s and Quater Oats … Coincidence? We do not think so.
In fact, breakfast is not at all beneficial for weight loss . It has even been proven that eating only two good meals in the day improves body fat loss .
Just try, for example, tomorrow morning, to have only one coffee or tea for your breakfast and write down how you feel. Do you feel tired? What is your energy level during the morning? Are you still hungry once your breakfast has passed? And if you want, share your experience in comment. Guide to Intermittent Fasting
If you are too hungry, you can not eat any more, eat! Then, write down the time you spent without eating (for example 13 hours), and improve it the next day (for example, pushing 30 minutes longer, but even 5 or 10 minutes is fine!). Try to improve until you arrive at 16 hours in a row, and, at that time, be very happy with you: you have just achieved a 16: 8!
Guide to Intermittent fasting continues..
Other questions / comments that often come up about intermittent fasting
I still do not feel able
Remember. Since the dawn of time, people have been fasting, in a religious context or not, with the goal of purifying their body of all its toxins and renewing it .
In 1966, ANGUS BARBIERI , an American patient with morbid obesity, fasted for 392 days ! Under medical supervision, he ate no solid foods and only took coffee and vitamin supplements. He lost 134 pounds and recovered from obesity. What is the relationship with intermittent fasting? It is to tell you that if someone can survive without eating for over a year, you are well able to skip a meal. Do you trust a little
It’s beautiful your stories, but I’m hungry me! I feel it in my belly!
Do you know the experience of Pavlov’s dog ? Ivan Pavlov is a Russian doctor who won the Nobel Prize for Medicine after having done this experiment in the 1900s. He noticed that the dogs of the laboratory began to salivate at the sight of the laboratory technicians even before their bowl was served. He then pushed the experiment further by analyzing the salivation of dogs conditioned to a stimulus. The first step was to ring a bell for several times in a row and then serve food to the dogs. Then another day he rang the bell but without food. At the time of the ring, the dogs started to salivate. The results of these studies show the existence of a conditional reflex stimulated by an element of the environment..
We, for example, every time we take the train or the plane, even if we had a meal just before, we want to nibble something! The train or plane would be our “white coat” that would trigger our reflexes of “hunger” (sacred ghrelin!). Our body begins to condition itself to receive food and this happens at the hormonal level.
To summarize, the more our ghrelin increases, and the more we feel our stomach empty or even painful. This reaction may be influenced by other factors than an empty stomach . A hormonal imbalance or an environmental condition can trigger this hormone. In addition, to not make our life easier, the reaction is exactly the same in all cases! Guide to Intermittent Fasting
It is important to know this mechanism and understand what is happening in its moments there to recognize hunger by reflex and hunger because we FAIM!
Do not worry, we have some tips to help you if it happens to you! Before you jump on the first food come, make a quick analysis of the situation and your feelings . Look at the time. If it’s time you’re used to eating it’s just a reflex that has come into place. Let pass a few minutes, concentrate on something else and the hunger should disappear.
If after half an hour, you are always hungry and have nothing to drink during the day. Drink a glass of water, a tea (preferably green for its effects on satiety), or a coffee. Often, we confuse hunger and thirst .
It can also happen that one is hungry by boredom . If you are doing an activity that does not stimulate you, do another that will interest you more. In this way, you should no longer want to comfort yourself with food.
From experience, fasting has allowed us to better recognize the different types of hunger we feel during the day. With the habit, we are more aware of our sensations and it has avoided us much unnecessary nibbling! We know when we eat because we are hungry and when we eat by simple greed. In the end, we noticed that if we only listen to our real hunger, we eat according to our needs.
Sometimes we eat more, but most often we eat less. And our weight does not move or even decrease. All that to say, listening to your body taking into account all the environmental parameters can allow us to better regulate our consumption of the day! Guide to Intermittent Fasting
Can I do physical activity during intermittent fasting?
The answer is yes of course! There is no contraindication to playing sports during a short fast. You can do any kind of activity without having to eat before your session. Remember, your body is able to produce energy from the stocks (glycogen and fat) available.
So what happens when you play sports while fasting?
First, the body will use the most easily accessible energy, glycogen, in the liver and muscles. During the first 24 hours of fasting, glycogen stores are enough to exercise without the risk of completely depleting stocks.
It’s after it gets complicated. If you practice long endurance sports like a marathon or a triathlon, if the body is not used to burning the stored fat, it will end up facing a “wall”. More glycogen available and difficulties in tapping into fat. Yet, as we all know, we store fat for energy reserves . And, depending on the food you have, it will be more or less difficult to draw on these stocks. Guide to Intermittent Fasting
How to use fat?
There are two ways to get your body used to using fat stores to produce energy:
Solution 1 : Train regularly on an empty stomach. The combination of a low insulin and a high amount of adrenaline created by fasting will stimulate lipolysis of adipose tissue (the breakdown of fat cells). Thus lipid oxidation is then possible (the burning of fat to produce energy). In addition, one study showed that after 6 weeks of fasting training, lipid oxidation by muscles was increased and blood glucose was more stable compared to people who ate before exercise. So once the body is adapted to this mechanism, our muscles become more efficient at using fat as a source of energy.
Solution 2 : Adopt a diet low in carbohydrates or very low in carbohydrates (like keto). The less you eat carbohydrates, the less glycogen you have in stock and the sooner the body starts to use its fat stores. When we are “keto-adapted”, we are already used to using fat (from our diet and our body) as fuel. From there, we have an almost unlimited amount of usable energy to play sports!
Moreover, many endurance athletes use fasting (sometimes combined with a diet low in carbohydrates) to improve their performance for a marathon or a trail. How to manage the lunch break with co-workers and the friendly moments with my friends / family?
Lunch time
Small scenario: You decided to do a fast of 24h and to eat only at dinner. The lunch break arrives and your colleagues come to pick you up to eat. You like to spend this time with them but you think that if you accompany them you may crack.
Our Tip Number 1: Before your fast day, tell your colleagues about your decision and your reasons. If they are open, they will respect your choice and leave you alone (or even support you!). And if they are less, it will be an interesting topic for lunch!
Then, D-Day, trust yourself and remember why you do it, it will allow you to accompany your colleagues at the table with a glass of water without frustration (François does it regularly and everything goes very well!) You will be even more proud after doing it! Moreover, if you do it regularly, you will get used to not eating at noon and it will become more and more easy to manage. Your colleagues will get used to it and you too
In the case of an OMAD (or URPJ , you are free to adapt the time of your meal according to your schedule. For example, if a business lunch is scheduled on Tuesday, Wednesday, an aperitif with your friends at 18h, and on Thursday, a welcome breakfast in your company. Even if there is more or less than 20 hours between each meal, you can make each of these events your only meal of the day. The goal is not to get frustrated or become antisocial. The benefits of fasting are not beneficial over time, not the exact number of hours you fast each day . Be flexible and make the most of your surroundings
What if I feel stressed or tired?
If you are in a stressful time / day or are feeling tired, focus on your body and your feelings (as when practicing mindfulness meditation). Take a deep breath, and analyze it. If you feel tremors, or your brain can no longer concentrate, and your stomach is really crying, you should consider stopping your fasting session. Never force yourself , this can create additional stress, and you may feel worse. It lasted only 14h instead of the 16h provided?
This is not a drama, there are other days when you will be in better conditions to fast In addition, remember that after 12 hours of fasting, the benefits are there and visible over time. It is not a “failed” fast that will “spoil” everything.
I have vertigo, cramps, what’s going on?
When doing intermittent fasting, it is rare (but possible) to have side effects that will manifest as headaches or vertigo, and sometimes cramps. During the fast, you eliminate more quickly your electrolytes (salt, magnesium, potassium). This leads to dehydration that can be balanced by salt intake. The solution is to add a pinch of salt in your glasses of mineral water, or to consume a broth of salty bone. And all will be well
Are there any contraindications?
In some cases, intermittent fasting is not recommended:
- For pregnant or lactating women as they need to feed themselves to feed their child.
- For people under 18 years old as they are growing and need to feed themselves to grow well.
- People who are very thin or have problems with food (bulimic, anorexic)
If you have diabetes (type 1 or 2) , gout , especially if you are on heavy medication, it is best to consult a doctor to be followed without risk to your health.
What to remember about all this
Now that you have all the weapons to get started, here are a few things to keep in mind for your first intermittent fasting :
Intermittent fasting is only practiced if you have chosen to do so. It is not mandatory. You DO NOT have to do it. We just think it’s a great idea. It’s MUCH easier to do than you think before attacking. That does not mean it’s trivial, but it quickly becomes
It is possible not to eat for more than a day without dying (otherwise we would not be there to write this article: D). We have been fasting for more than two years for François, and nearly a year for Elodie. Mostly on intermittent fasting, 16: 8 or OMAD (now you know what it means , and we even tested some longer fasts, 2 to 5 days. We can confirm this: we feel even better on the days when we eat less in general.
We do not eat after , on the contrary! It even allows us to lose weight when on a platter.
It saves time and “zenitude” . Our life is much less organized around meals. If we find ourselves in a situation (event, movie outing, long walk in the forest) where we know we can not eat (for lack of time or availability of food), it does not matter! And it’s very liberating.
There is a difference between real hunger and eating by greed / habit.
Learn more about guide to intermittent fasting from Shivani Sikri : Best Dietician in India
READ MORE : Low Carb – The Best Diet Principle
READ MORE : Eat Fat To Lose Weight on Ketogenic Diet
Guide to Intermittent Fasting ends..!