Fasting - ALL YOU NEED TO KNOW
(Intermittent fasting, warrior diet, prolonged fasting)
Welcome back warriors!
Fasting or intermittent fasting have been all over the internet the last few years and I have already referred to that in previous articles and posts. Lately i shared on my
Instagram that since my schedule has decluttered a tiny bit i am back to regular intermittent fasting, which i have been practicing for years. I got a lot of questions about what it is, how and why to practice as well as the long-term effects of fasting.
DISCLAIMER: I am not a doctor, therefore, the content here is for educational purpose as well as to provide you some guidance over scientific literature review plus my own experience into fasting (as well as my clients' feedback). I am a fitness coach, athlete and also certified molecular biologist, so the information below is facts, research and principles, backed up with tips from research and experience. For a healthy person, fasting (
WHEN PRACTICED CORRECTLY) can only be beneficial. However, certain groups of people with underlying health issues, might not be good candidates for fasting protocols due to hormonal interference with medication or other complications. If you are unsure, ask your physician and establish supervision if that is necessary. Lastly, if you want to practice fasting (intermittent or prolonged), do the favour to yourself
AND READ THE WHOLE THING. The better you are informed, the more prepared you will be and consequently, you will avoid a lot of mistakes that could potentially backfire and sabotage your goal (or health). And with disclaimer out of the way, here we go:
Since it is impossible to provide all the necessary information in a single IG post, i decided to analyze the topic (but still keep it easy to follow) while addressing as many of your questions as possible. Here we go:
What is fasting?
Fasting is technically the state when your body has digested the food, absorbed all the nutrients and has entered a phase when it is deprived of food and initiates a cascade of physical processes (
ketosis, autophagy, growth hormone increase, decrease of insulin and cell rejuvenation) depending on how long into fasting your body is. Ketosis begins 12 hours after the consumption of last meal. This is just a very brief introduction and I am going to elaborate on the processes in a subsection later on this article.
What are the different fasting types?
I understand that terminology might bring a lot of confusion while reading about it, so i will aim to clarify it. Different fasting terms refer to different timeframes when you consume food (feeding window) and when you don't (fasting window). There are different ratios and durations of fasting and feeding windows which trigger different metabolic and immunological responses. Here are the most common ones:
Intermittent fasting (IF):
As the term describes, intermittent fasting (aka IF) alternates feeding and fasting windows, usually within the span of 24 hours. Most common is the 16:8 (16 hours fasting, 8 hours feeding window) which is frequently called 'Lean gains' fasting. Let's see an example: If you skip your breakfast and start eating your lunch at noon (12:00pm) then your 8 hour feeding window is between 12:00-20:00. You need to consume all the daily caloric intake within these hours. If you aim for fat loss you can have a SMALL caloric deficit, but you still need to consume all your calories within this timeframe.
Warrior diet:
This is another form of intermittent fasting with a smaller feeding window, often called 20:4 (20h fasting, 4h feeding window). This one is particularly challenging, and should be practised after one has practised typical 16:8 fasts for a good amount of time, to ensure that the body has adapted to fasted state and doesn't get overwhelmed. That one can be particularly effective for people who aim for muscle gain, as scattering the calories as pre and post workout meal can yield a good anabolic result without adding too much fat during the process.
Prolonged fasting:
Any sort of fasting that includes more than 24h of fasting window. Most frequent are 24, 36, 48 or 72h of fast that happen once a week, once a month or anything in between. That can be more challenging during the fasting state, can strengthen the immune system (if refeeding is done properly to replenish the lack of nutrients) and offers some more flexibility. For instance, if you have a prolonged fast in a week and then you travel the next, you can have more freedom with food and caloric intake.
Alternating fasting:
That usually incorporates 24h fasts, alternated with normal non-fast days. That can be 1:2:1, one day of fast, followed up by 2 normal days and then a day of fast. Other options have been 1:1:1, basically alternating one day of fast and then a normal day, followed up by fasting etc. There are many different options for that.
Why to fast?
Fasting has a lot of benefits, which explains why people fast for different reasons. As i mentioned earlier, fasting helps you regulate your meals. That alone can help you create a specific and consistent feeding pattern for your body, therefore regulating your hormones, energy levels and sleep pattern around it. It is particularly advantageous for people who suffer from binge eating, insomnia, diabetis and those who skip meals. Additionally, it can help a lot with emotional/binge eating. Since your blood sugar drops and remains low and stable, you prevent those spikes that cause uncontrollable hunger. Through practising fasting, you exercise discipline and you gain control over your cravings. Moreover, since you have to squeeze all your daily calories in a particular feeding window, you will enjoy larger meals and feel much more satiated, without having the 'stress' of restriction that you'd have if you scattered those meals into larger timeframe but much smaller portions. Furthermore, a consistent eating pattern can help with digestion issues, bloating and water retention. Lastly, during prolonged fasting you can boost your immune system. Autophagy is a process that helps your body get read of damaged cells or proteins that are not 100% normal/functional as they should be, something that doesn't happen while you are in well-fed state.
What's the relation between fasting, fat loss and muscle mass?
Let's begin with the obvious: while you fast you have no caloric consumption while you still burn calories for your basic metabolic processes (breathing, regulating temperature, etc), moving around, performing tasks and even working out. That means that you are likely to lose weight. Some common misconception is that your muscle mass is going to be catabolized (aka consumed) for energy, That is not true for intermittend fasting, as you will still consume sufficient calories (if practised correctly) during your feeding window. High protein intake as well as regular resistance training aim to preserve and stimulate your existing muscle mass, respectively. For prolonged fasting protocols, research has shown that the body can endure up to 3 days of starvation (72h) without decrease in muscle mass.
Whar about fat? As mentioned earlier, when you're in a caloric deficit (even a slight one) you tend to lose weight. Weither that weight is water, fat or muscle depends on:
1) the macronutrient ratio. High protein intake helps you to maintain your muscle mass and get rid of excess intra-cellular water retention.
2) hydration level. As protein discards the excess water, trapped within the cells, it is very important to keep drinking a lot of water so that your body doesn't get the message ' I am getting dehydrated, i should save up some, just in case'. Additionally diets rich in protein, require you to drink a lot of water to ensure a proper function of your organs.
3) exercise. Similarly as high protein intake, strength training stimulates your muscles and triggers growth hormone signaling, therefore preventing your muscles from being seen as 'non useful' and therefore an 'easy to go' energy source, from your body.
4)the duration and consistency of your fasting regime. I mentioned the term 'ketosis' above. In normal well-fed state, the fat is the least accessible/preferable energy source for your body (which explains why fat is so stubborn to lose). That makes perfect sense because biologically we store fat to have a safety deposit just in case we starve, but fat resservoire also participates in hormone regulation. Therefore it's logical that your body doesn't really want to get rid of it, that easy.
Ketosis takes place after 12h of fasting and describes the process where your body begins to break down fat and your liver transforms some of this fat into ketone-bodies, as by-product, in order to use it for energy supply. Ketones serve as an alternative to carb-derived glucose (that you normally use during well-fed state) but are actually far more beneficial because they produce less inflammatory by-products, they can decrease cell damage and neuron death, and even stimulate the production of a brain growth factor (BDNF). Consequently you are likely to have a better mood, focus and clarity when you are on fasted state. Personally, I found this as a big asset on my studies' exam periods, however my body was already adapted to fasting, by the time i used this 'trick' during my exams. Although ketosis begins after 12h of fasting, the highest production of ketone-bodies takes place at 18+ hours, when your body is in total fat-burning mode. So
if you're mainly after fat loss,
warrior diet (
20:4) or
1 full-day fast a few times per month, might be more advantageous for you. Note that ketosis can also take place during eating if you absolutely deprive yourself from carbohydrates. This is the principle that most 'commercial speed weight loss' diets follow. Indeed, depriving yourself from carbs will make you lose weight fast but since you can't sustain this forever, it is going to backfire (yo-yo effect) right at the moment you begin to eat normally, not even to mention the damage on your health from totally neglecting carbs. Especially if you want to lose fat for aesthetic, competition or health improvement reasons, please
be mindful, consult a doctor and don't shut off ALL the carbs. Rather circulate your carbs pre and post workout, in your feeding window.
What are the perks of prolonged fasting?
Now you might be wondering, if fasting is so beneficial, why do people performed prolonged fasting instead of an easier intermittent fasting? And you are right. Intermittent fasting is a 'sweet spot' where the fasting window is bearable ( considering that you should be sleeping at least 8h of it) and provides a lot of benefits. However you don't unlock the 'full package'.
- As i mentioned above, your body starts burning some serious fat at 18+ hours of fasting. That super fat-burning state won't be accessible with intermittent fasting methods like (12:12, 14:10 or 16:8).
- Additionally, after 24h of fasting, autophagy takes place and your body cleans up faulty proteins and damaged cells from your body. That's pretty advantageous as some diseases (like Alzheimers etc) are associated with damage on neurons and/or other cell types. Aging. stress. sleep deprivation, unhealthy lifestyle are all factors that can cooperate to induse malfunctions in your body, and therefore, diseases. Autophagy takes care of that and reduces the disease potential significantly. Exercise while fasting can enhance the autophagy in your body.
- Earlier i refered to growth hormone increase. Let's see what is going on with it. At 48h of fasting, your body produces 5 times higher levels of growth hormones (like the brain growth hormone i mentioned above) compared to the moment you consumed your last meal. By that time your body is 'hungry' and this signaling also stimulates growth hormone production. In simple terms, your caveman body tells you 'looks like you haven't found food lately, here you go, get some growth hormone to maintain your muscle and have the capacity to go out there and hunt your prey'. These are super good news if you're concerned about muscle growth/preservation because you can still burn a ton of fat while keeping your precious muscle mass intact.
- Do you know what else starts at 48 hours? Self-renewal of your cells. Your body becomes more efficient to handle stress (in this case food deprivation), making it easier and easier for you to adapt and integrate fasting in your lifestyle. Last bur not least your blood and hematopoietic stem cells can be regenerated,
- Insulin reduction takes place around 54h into your fasting. That is a super good thing because it can make you more insulin-sensitive (aka. the insulin performs its job better). People with slow metabolism, diabetics and pre-diabetics, all have insulin-resistance (aka their body is resistant to insulin's work and therefore the task of blood sugar regulation is not completed properly). If you want to lose FAT, you need to get yourself more into the insulin-sensitive side. But benefits don't end here. Reduced insulin levels together with autophagy decrease inflammation in your body and make you less prone to suffer from chronic diseases and cancer.
- At 72 hours of fasting (3 days) your body is in the greatest spot from immune and balance point of view, as your white stem cells are regenerated, they are healthy and active against anything that can suppress the well being of your immune system. These findings have been observed even at cancer patients who undergone chemotherapy.
How do you integrate fasting in your lifestyle? What happens to social life?
Fasting can actually help a lot with keeping you on track without sacrificing the social eating aspect. If you manage to synchronize your feeding window with let's say a party, family dinner, special occasion, you can enjoy a larger portion (always within your caloric intake range) without being stressed about 'cheating' on your diet or fasting goal. Furthermore, fasting can provide you enough hours of the day when you don't have to think about food, cook, eat and do the dishes. That means, fewer distractions and more quality time to focus on your tasks (work, reading, whatever). Lastly, as i mentioned above, if you have already planned a special occasion (day or week) when you'd like to feel free, eat and enjoy without the toll in your diet, then fasting can help you prior and after that, as well.
Can I exercise during fasting?
Yes you can. Your energy level is obviously going to be lower so it is improtant to not expect 100% efficiency and be aware of how you feel. It is better not to train if you feel lightheaded or sick. Usually, the more mild forms of fasting (like 16:8) are easier for the body to adapt and regulate the energy level, so after you get into it for some days or weeks, your body should be able to be functional while you are on fasted state. It is better to exercise right before you begin your feeding window, to burn the maximum amount of fat and then refeed to fuel up the muscle recovery and growth. Keep in mind that if you are new to this or if you are experienced but strive for prolonged fasting protocols, you should avoid long high intensity training just in case. You should particularly be concerned about your hydration. During fasting, the level of electrolytes can drop due to deprivation from food (and also sodium), so it is very likely that if you sweat a lot, you will feel dizzy after a while. As electrolyte powder or tabs can contain sugar, i have found my own way to combat this by making an electrolyte drink at home. I mix 1/2 teaspoon of himalayan salt, one tbsp of lemon juice, a few drops of calorie-free sweatener in a big water bottle and consume it during my fasting or training.
Is fasting for everyone?
NO. Although fasting is flexible in terms of feeding/fasting window ratios, it can be dangerous if not practised correctly, even more from people who have medical issues. It is recommended that you ALWAYS consult your physician before starting your fasting journey, to ensure that you are fit and safe to do so. If you are about to do fasting, comply to do it RIGHT.
Common mistakes on fasting? What to eat/not to eat. Further Tips.
And there we go with a very important part. Fasting, if practiced correctly can have many benefits for you. However, if practiced wrong it can totally backfire, especially to people who take medication, have any underlying issues or are obsessed with weight loss.
Additionally there are some mistakes people frequently do without realizing it, which inhibit the fasting process:
- Fasting means that you should not consume anything that has calories. That being said, you can drink coffee (black) or tea, WITHOUT sugar, atificial sweatener with calories, milk or cream.
- If you need to take medication or supplements (like vitamins and such) it is wiser to consume them with a meal, within your feeding window. That should be under consideration when you establish your fasting timeframe.
- During your fasting, a capsule of omega 3/6/9 capsule can be okay, without breaking your fast.
- DRINK YOUR WATER. Water has zero calories and is absolutely essential for you, so keep yourself hydrated, especially during fasting window as it can relieve you from hunger when the blood sugar levels begin to drop. Coffee can have mild appetite suppressive impact on some people, so it's a good friend during fasting as well (again, BLACK coffee).
- Diluted apple cider vinegar (half a spoon in a big bottle of water) can also help with hunger and may promote fat burn (although there are not many valid studies to support that 100%). This needs to be practiced in caution, because extensive consumption of apple cider vinegar (especially undiluted) over a long course of time, can damage your teeth, irritate your throat or even cause ulcers due to the high acidity.
- If your only purpose of fasting is to lose fat, then you are mainly interested in ketosis state (that's when your organism produces ketones and switch to fat burning state. In this case you can consume some calories originating entirely from fat ( like egg yolks, bone broth, oils like coconut oil in your coffee) etc. That will break your fast, but it will NOT break ketosis state as long as you do not consume carbs, This can be advantageous is you are fasting specifically for fat loss and you have to take medicine during your fasting window. Personally that doesn't really work well for me because i am not very tolerant to high fat content, so it is subjective and up to you. If you are after the immune boost and further benefits of prolonged fasting, stay away from caloric consumption during your fasting window.
- Fasting doens't mean you starve yourself. During your feeding window you should consume ALL the calories you would normally do, in the frame of the day. If you are on diet for fat loss purpose, your intake can have a small deficit but DO NOT GO OVERBOARD with caloric restriction. If you do not feed properly during your feeding window, you risk a ton of negative health consequences that can be pretty serious. You certainly DON'T WANT THAT. Be reasonable.
- It is normal to be thinking about food when you begin your fasting journey, A great way to combat that, is to use the 'awake' hours of your fasting window to do tasks. Get done with all sorts of household, computer work, errands, meditate, exercise, indulge in your hobbies, read, watch a movie, call someone to chat etc. Being busy during these hours will make you less likely to feel hungry and will help you with delivering your tasks and being more time efficient.
- As i know that can be triggering for some people, i have to address it out. Studies have shown that bullimic people have taken a big benefit after sticking to fasting lifestyle, in the long run because they regain control of their eating. People who suffer from anorexia, find it easier to go through long periods without food, however they usually skip meals during the refeeding process, and end up with a huge caloric deficit. That results to muscle loss breakdown, further decline of health, metabolism shut down, amenorrhea (loss of period in females) and a ton of hormonal deregulation along with more serious health problems.
- If you take supplements, keep in mind that some of them can be sugar free (like fish oil tablets or multivitamin tablets, pre/probiotics and pure collagen) and are less likely to break a fast, whereas, others have sugar or many calories like multivitamin gummy bears, BCAA's, protein powder etc. Depending in which category your supplements fall into, you can find their best spot during your fasting/feeding frames.
- In prolonged fasting (24+ hours of fasting window) you can technically consume around 500kcal daily (preferably scattered) as long as they originate from fat (ex. almonds) and/or low carb, low protein foods like green leafy vegetables They can inhibit autophagy level a bit but they will most likely not disrupt your ketosis.
- Upon my experience, if i am about to exercise, i usually do it before my feeding window begins. I am usually VERY hungry after a workout so i prefer to have a large caloric frame ahead and ensure that i am satiated and within the calorie intake limit, rather than having to 'restrict' myself in case i ate prior to my workout.
- As i mentioned above, fasting is a LIFESTYLE and should be followed in the long run for someone to ripe the pure benefits (whether that is solid fat loss or immunity perks). That being said, fasting is not for everyone (health and mentality wise) and certainly not ALL protocols fit everybody. Take your time to build up your fasting tolerance progressively and under control. Begin with relatively easy goals like 12:12 (that should be easy if you get a proper 8h sleep and eat 2-3h before bedtime). Give yourself time to adapt and progress. Observe your body's reactions and make sure to seek medical advice in case you are unsure, afraid or experience a decline in your health.
- Following the previous tip, most people are concerned, how will they manage to pull through the fasting hours while they are awake. Best solution to that can be to eat a few hours before bed time (avoid sugar and simple carbs as they can cause huge spike in your blood sugar, which in turn, when it drops will make you suffer from hunger). Make sure your last meal is rich in fat and high quality protein. Then, benefit from a long sleep and just like that you can easily have a 12h fast already by the time you wake up. For most people skipping breakfast and beginning their feeding window with lunch is more functional because in the morning you can easily get cought with getting ready, going to work etc and forget about food, while you save up some extra time. For other people it works better to fit food in the time of the day when they are more physically active. In people who do sedentary work, it might be more efficient to fast during work hours, both to be occupied and not think about food AND to not disrupt their focus.
How to refeed after a fast?
After your fasting window is over, you need to break a fast. You have to keep in mind that for your body, deprivation of food is a form of stress. During your fasting, your body finds coping mechanisms to adapt and not be 'stressed' anymore under these circumstances. Therefore, when you initiate food in your body again, you need to be 'gentle' and not 'shock' it, right on the time that it managed to adapt. In simple words, that means you should avoid high sugar, simple carbs, processed foods in your first meal after a fast. Give your body space to adapt again, by consuming a balanced meal consisting of high protein, moderate fats and complex carbs (like oats) that will not cause a rapid elevation of your blood sugar right away. Fit most carbs in the middle of your feeding window and reserve some more protein and fats for the last meal before you fast again.
Can i eat whatever i want during the feeding window as long as it is within the daily caloric intake goal?
Technically yes. If you establish a daily caloric deficit and stick to it, you are likely to lose weight weither these calories come from 100% healthy, quality foods or something else. However the way these calories are going to translate in your health, physique and functionality is a whole other story. It would help to perceive food as fuel for our body and processes, therefore, choosing high quality foods for most of the meals can yield the best possible results in body composition, performance and overall health. Especially if you are interested in the immune boost, autophagy and such, it would be totally unwise to sabotage your body's effort during fasting, with unhealthy food on your refeeding. Strive for well balanced meals.
How long does it take before you see results from fasting protocols?
It really depends 1) on the individual and 2) the goals you have out of it.
Different organisms need different time frames to get used to different feeding patterns, but that also includes how consistent you are on practising fasting. The body loves 'routines' because it learns the pattern, develops adaptive mechanisms and then just follows it, without spending energy to 'adjust' all the time in different conditions. For example, if your goal is to lose fat, just as it happens with normal caloric deficit diets, you will probably shed fat faster if you have a lot of weight to lose, compared to a much leaner person. Just as a reference, in a span of 10 weeks, most people can already start to see a noticeable difference in their energy levels, various body responses, mental clarity and body fat levels. In my personal experience, after years of fasting for consistent periods of time, every time i begin a fasting protocol, i can already see results within the first week, but that's because I am very observative and mindful of all the functions of my body. If you are new to it, you might not be very observative over your digestion for instance, so don't worry about results. IF you practice correctly, they will come. Just like everything real that originates from hard work, it just needs time.
That's all folks!
I hope this guide has been sufficiently informative for you. I tried to break down the advanced science into facts-easy to follow and you now have everything you need to begin your journey safe and successfully. I integrated all the information i believe someone needs to perform fasting consciously but i highly encourage you to research more through valid sources and/or consult your physicial to ensure you can safely perform fasting without any risk. My contact information below are available for you in case you have questions or requests for future articles. Until our next catch up, stay active, safe and healthy!
Best,
Irinä
