The three-day water fast

Dr Tallis Barker, water fasting coach

Of all fasts, the 3 day water fast is in many ways the most important. Three days is the period your body needs to unlock your healing metabolism and begin reaping the benefits. These three days are also the stepping stone required to move on to even longer fasts (such as the 7-10 day water fast and more prolonged fasts), in which the deepest healing can occur. The more you practise the three-day fast, the easier you’ll find water fasting of any length.

I’ll be honest with you, though. In the beginning, the 3 day water fast is also often the hardest.

Because of this, it’s important to do everything you can do to maximise your chances of a smooth experience. This can include following a well laid-out plan, such as that found in: The Complete 3-Day Water Fasting Program® and Living on Water®. For those who need more personal contact, I also offer online consultations and coaching.

Whether you choose support or to go it alone, it’s definitely better not to try and bite off more than you can chew 🙂 with a 3-day fast until you feel comfortable with one-day (36-hour) water fasts. This is because a 3-day fast really is a quantum leap ahead in terms of what it demands from your body.

What are the challenges and benefits of a 3-day water fast?

Before you gain greater experience, most of the challenges of the three-day water fast are physical, as your body learns how to enter the state of ketosis. Ketosis is the process of burning fat directly from adipose (fat) tissue, which is achieved through the production of so-called ‘ketone bodies’ in order to metabolise the fat. Unless you happen to be following an extremely low-carb diet, this is entirely different from how your body normally extracts the energy needed to power each cell. As a result, the vast majority of people never experience ketosis in everyday life, and rely instead on metabolising carbohydrates until the day they die. This is a real shame. We have two eyes, and we use them both. We have two arms and two legs, and we use each of them. We also have two metabolisms: our everyday carbohydrate-based metabolism, as well as ketosis. They each serve their own function and offer their own benefits.

There are two huge benefits of getting into ketosis while you fast. First, because you’re burning fat and not eating, your body frees up a lot of extra energy for healing. (It’s estimated that digestion accounts for about 30% of your total daily energy needs.) Second, because you’re burning fat cells, you gain the potential to burn up and cleanse toxins which have been locked there for years and years. This is a different mechanism from being on a low-carb diet and burning fat in everyday life, because in this case essentially the same fat cells are used for energy, over and over. In contrast, deeper levels of fat remain untouched: with their toxins accumulating within.

What happens on a 3-day water fast, day by day?

Day 1:
Of course, the first day feels the same as on a one-day fast (described in greater detail here), as you slowly exhaust your reserves of carbohydrates, which are stored as glycogen mostly in the liver, as well as in the tissue surrounding your muscles. Psychologically, though, you should feel much more comfortable – given that you already have experience in surviving one day without food. Surviving three days without food is simply an extension of this, and so hopefully you’ll be freer to concentrate on the physical changes taking place inside you. You may indeed find yourself facing your ego over these three days, but it’s more likely to take the form of facing your addictions to food rather than facing your ego’s existential fear for survival.

Day 2:
By the beginning of the second day your glycogen reserves will have run out. At this point, how you feel depends on how much experience you have in fasting. Nowadays when I fast, I feel great because my body has made the switch to ketosis in tandem with my glycogen stores running out. In other words, I don’t suffer any ‘power loss’. In fact, I usually benefit from even fuller energy towards the end of the first day because I’m powered by two sources: my usual carbohydrate-based metabolism (before the glycogen stores completely run down), as well as by ketosis – which starts to kick in a couple of hours after I miss my first meal. It’s a great feeling, and, in time, you can look forward to it too!

However, if your body isn’t adapted to ketosis, things will probably be rather different… Your glycogen fuel tanks will hit empty, and your body will have to (continued below)

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search for an alternative power source – and quickly too! The burning of fat through ketosis is highly efficient, but the problem is that your body hasn’t yet learned how to easily access this metabolism, because the chemical reactions involved are so different from what you’re normally used to. Instead, the next closest source of energy is through burning protein – and this comes from metabolising your own muscle tissue. Don’t worry, you’re not going to lose any significant muscle mass. We’re talking about only a few hundred grams until your body has started to perfect ketosis by the end of the third day. From this point on, any further loss of muscle mass is minimal.

In the meantime, though, you’ll probably feel extremely low on energy. Your muscles may ache, especially in your legs and back, as your body sacrifices muscle tissue. Headaches are also common, both from low blood sugar and lack of energy, as well as from the beginnings of detoxification. Dull aches around the kidneys are also common, as your kidneys start to work overtime, flushing out the first toxins from your fat cells as well as the extra acids caused by metabolising protein. If so, make sure you’re drinking enough: at least a quart/litre or two per day. There is no fixed minimal limit to drink. This depends mostly on a person’s level of toxicity. The higher the toxicity, the more you’ll have to drink. Many people drink 3-4 quarts/litres a day.

I don’t want to lie to you. Personally, I feel that too many books and websites on fasting paint a rosy-coloured picture of how you’ll feel. Telling the full truth might turn off potential converts to water fasting… Yes, perhaps you’ll feel like a million bucks. But for the first couple of three-day water fasts it’s more likely that you’ll feel pretty awful, not entirely dissimilar to how you experience the flu: with aches and pains, and a general lack of energy. But don’t worry. And don’t give up at this point!!! You’ll survive. Just hang in there. All these symptoms will pass.

Day 3:
The third day is more or less a continuation of the second, both in terms of the physiological processes taking place, as well as how you feel. Many people feel at their lowest at the end of the second or at the beginning of the third day. Generally, though, things start to improve after this, as the switch to ketosis is completed.

If the toughest part of a fast is getting through the first three days, then isn’t it worth diving straight into a longer fast and reaping the benefits of what you’ve suffered through? Maybe. If you have the energy to do so, then by all means! Most likely, though, your first few three-day fasts will leave you feeling drained both physically and emotionally. There’s no need to do any more at this point. Three days is enough. Mission accomplished. You’ve successfully awoken your body’s healing metabolism, which you’ll be able to rely on increasingly in the future. You’ve also already experienced a significant degree of detox. Instead, take on a longer, more cleansing fast once your body has more fully acclimatised to three-day fasts.


At the end of the third day, enjoy a glass of freshly squeezed orange juice and pat yourself on the back. Unlike longer fasts, there’s no need for a long transition back to eating. Nor is there any need for a long transition before the fast itself. However, do keep the first few meals light: mostly just fruits and/or vegetables (just as the last few meals before the fast should also be light). Don’t eat too much! If your ego is telling you to gorge yourself, avoid the temptation and try to honestly follow your appetite. Your stomach will have shrunk, your digestive system will have slowed down considerably, so you need a little time to get things up and running again. If you do follow your appetite, you’ll find you’re eating normally again in a couple of days.


— The deepest detox (click here)
— Overcoming addictions (click here)
– Enjoy the gift of food (click here)

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  1. Armando says

    Hi Tallis

    I hope it’s ok to still comment on this post, even though the last comment was from some time ago.

    I’m still very new to fasting and have been doing the weekly 36h fast on and off for some time.
    As I’m very slim, I honestly don’t think (or feel) there is much body fat on me, mainly skin and bones (with some strong muscles in-between ;-))

    There have been many fasting days where I really feel weak in my body and tend to just lie around and sleep, which feels kind of unhealthy as I feel really bad during that time. I’m still trying to figure out how much of it is psychosomatic vs. the body actually reacting like that.

    Admittedly, I do feel an addiction to food, it’s just so yummy. We eat pretty much only organic and local fruit and veg, so it’s just healthy stuff! This makes it more difficult for me I think, because it’s not like I binge on “baddies”.

    Do you have any tips on how to overcome this mega-lethargy that hits me?

    Thanks so much for all your wonderfully written and motivating articles here, I’ve been reading them happily and learning a ton on the way =)

    Kind regards,

    • Tallis Shivantar says

      Hi Armando,

      Thanks for writing. Of course it’s okay to add a comment here :-).

      There can be several reasons for “mega-lethargy” (nice way of putting it by the way!), both physical and psychosomatic.

      First, you mention that you’re skinny. In my experience the single most important factor influencing energy levels while fasting is the amount of body fat you have. The more fat, the more energy you’ll feel. Simply, the body knows you have plenty if energy to burn! If you don’t have much fat, on the other hand, the body is much more inclined to conserve your fat reserves, which means it burns as little as possible, which means there’s simply not very much available energy.

      Second is blood pressure. Blood pressure tends to drop while fasting. So if you already have low blood pressure in everyday life and it drops even more, you can end up feeling very low on energy.

      Third is detox. When your body is strongly cleansing, there’s less energy available for just getting through the day, and you feel lethargic.

      So far these are all physical factors which you can’t influence very much while fasting.

      Psychologically, food addictions can also lead to low energy, because a lot of emotional energy can be spent resisting the fast, which then leaves you with less physical energy.

      All I can say to you is that low energies will improve – at least to some degree – if you continue to practise fasting, because your body will become better trained to deal with the changes taking place. In the meantime it’s best to try and accept your low energies and not fight them. Just take it easy, rest, and don’t feel guilty about it!

      Hang in there!

      • Armando says

        Hi Tallis

        Thanks for your swift reply and comforting words =)
        It’s great to hear that this will improve over time, which is something I really hoped for, because I truly do believe in the healing powers of fasting. Can just be a bit challenging to see that on those low days.

        The reason why I posted my comment on this 3-day article instead of the 36h one, is that we’ve just finished a 3-day fast yesterday! And it went supremely well 😀 I had enough energy to not feel tired / drained and was up and about doing smaller things (mainly light gardening).

        So from that I can see that there is some psychosomatic-ness at play, playing with me 😉

        Much more challenging was yesterday though, the day we ended the fast. My mind was going literally “nuts”, with this huge need for nuts (specifically walnuts, to clear any possible curiosities). We had some fruit and steamed veggies around lunchtime and I could really feel them there in my stomach later that evening. Same happened with some banana that I had later on, my stomach hurt a little even! So I opted to not eat more and let my body figure itself out.

        I’m really super happy to have had a very mild experience of what it’s like when the stomach “isn’t in” yet.
        Reading this 3-day fasting article really helped me through this, as I knew what could come.

        So thanks again so much!!


        P.S. Enjoy the ride of your current fast, may it flow and clear out what is ready to go.

        • Tallis Shivantar says

          Hi Armando,

          Congratulations on your 3-day fast!
          It’s funny how the hardest part of a fast can often be what happens afterwards – especially if the fast itself proceeds smoothly.

          Your nut craving is something to take seriously. After a fast we all often get cravings. The question is whether the inner voice driving the craving arises out of addiction/ego or a genuine nutritional need. Given that you weren’t craving sweets, caffeine (or even flour-based products or, in certain cases, meat), it’s pretty likely that the craving for walnuts reflects the body’s attempt to compensate for some kind of nutritional deficiency in your everyday diet. Walnuts are packed with minerals. Could you be low on certain minerals, for instance? They’re also relatively high in protein, so especially if you’re vegan or vegetarian, it could be a sign that you’re low on protein.

          Sometimes, the foods we crave after a fast shouldn’t be re-introduced immediately. Walnuts, for instance, are relatively difficult to digest, so you wouldn’t want to immediately refeed with them. However, after your digestion has properly awoken again, these kinds of foods can play an increasingly important role in your post-fast diet.

          Hope this helps,

          • Armando says

            Hi again Tallis,

            The re-feeding for me after the 3-day fast was very strange, as I didn’t get the feeling that my digestive system had kicked in again. This stayed for various days. I ate super-micro amounts of food, was in bed by 00:40 (without planning, to the minute for several days!) and needed only between 5 and 6 hours of sleep, feeling fully energised and bouncing all day. This feeling was amazing, as I was also super-focused in all that I did. I didn’t need to “plan” things as they just fell into place as I was doing, totally in the flow with everything.

            I would have loved for this to have stayed like that, but I felt it would come to an end at some point, as the amounts I was eating were negligible and I had no idea about the nutritional value that I was getting. My food appreciation during this time was epic though and I really “felt” like I was absorbing every last bit of energy from what I was eating. Almost as if I was also digesting something metaphysical along with it.
            Every time I tried to eat a bit more, to push myself back to “normal”, I could feel some unease in my stomach.

            Then a week later my body really asked for food and I started eating again, pretty much stuffed my face though. It was way overboard but I just needed to fill myself. There was no uneasy feeling or anything afterwards, it was as if the food just disappeared inside me, as if paying back for the credit I had been living on the past week.

            Now I’m back to normal, trying to keep my eating in check, as I’m a forever-skinny type of person who can eat endlessly without gaining any weight. So I do feel like I should be more aware and appreciative of food and the whole ceremony of eating.

            Also, I’m in a constant dilemma of knowing if it’s my body asking for something, or me wanting it. It just sounds so easy to “listen to your body”. This seemed quite clear when I started eating again after that week of micro-dosing food, but in general my body is pretty quiet.

            Do you have any tips regarding this? What does “listening to the body” sound like to you?

            Kindest regards,


            • Tallis Shivantar says

              Hi Armando,

              Thanks for sharing your experiences. It sounds to me like your body wanted to fast for more than 3 days, which is why you had difficulty in starting up your digestion. As much as many people have trouble keeping to the full length of their planned fast, sometimes the opposite can happen, and the body wants to continue!

              Your question about ‘listening to your body’ is totally justified. Distinguishing between the true voice of our body and that of our ego (which wants things) is the hardest thing in the world! The same applies not just in fasting but in the rest of life… The main thing is just to keep being aware, so when a craving comes up you don’t just slip back into habit without thinking about it. The more you listen to your body, the more your body will speak to you.

              In terms of ‘what listening to the body sounds like to me’, the true voices are usually more subtle than those from the ego! Nevertheless, there are cases in which I’ve confused genuine need for addiction. For instance, over the last few years, several fasts of mine have ended with a strong craving for meat – which was particularly strange for me as a vegan! I always assumed this was a false voice or perhaps an old addiction, but recently several apparently unrelated symptoms made me realise that actually I’ve become protein deficient over those same last few years. So in retrospect, no. This was a true voice in the sense that my body was craving protein, and meat is the densest form of protein.

              You already experienced tuning into the body when you were micro-dosing, so hopefully that will provide some sort of model. If in general, though, you don’t notice what your body is saying, then I’d suggest trying to tune into your digestion more consciously AFTER each meal. How does your body feel about what you’ve just eaten? It will definitely give you an answer. Continue to ask this question not just in the first minutes after eating, but also for the first hour or two. After you’ve built up some communication following mealtimes, you’ll probably have better luck BEFORE eating too, when your body is most likely to try and guide you in terms of what to eat.

              Hope this helps,

  2. Nicole Geyer says

    Hi Talis,
    I have been on water fast for 10 days now and would like to do it for 40 days. Is there anything special to consider in this long time? Many thanks for your great blog and the best regards from Germany,

    • Tallis Shivantar says

      Hi Nicole,

      Your welcome 🙂
      To answer your question, a lot depends on your state of health. If you’re healthy and well nourished – and I mean in terms of nutrients, not necessarily weight – then you should be fine. The biggest potential for things going wrong will be immediately AFTER the fast, during the refeeding period. It’s REALLY important to get the first couple of weeks right in this respect!!! There will be temptations to overeat. And eating the wrong kinds of food or simply too much can lead to refeeding syndrome. If you have any doubts about this, I have a 67-page PDF called ‘How to break a water fast of any length and manage refeeding’, which covers everything you need to know.

      However, if you’re not healthy, are suffering from an illness, or haven’t kept up with your nutrition lately, then I’d suggest discussing the particulars of your case with a fasting coach.

      Hope this helps,

  3. Crystal says

    Should you have lemons and lime with your water

    • Tallis Shivantar says

      Hi Crystal,

      Thanks for your question. Ultimately, the answer depends mostly on the reasons that you’re fasting.

      If all you care about is the physical side of water fasting, then a LITTLE lemon or lime isn’t going to interfere with the biology of the fast. However, in my opinion water fasting can and “should” go deeper than just this. Fasting touches on the deepest habits and addictions, and adding the ‘excitement’ of taste denies you the possibility of fully facing your ego – the element of our personality which clings to habits and addictions in the first place.

      Personally, the only time I’d recommend adding citrus like this is at the very end of a water fast lasting at least a week. Doing so helps to provide a final detox for the liver before it has to return to its everyday job digesting food. Otherwise, it’s best just to leave your body alone and let it get on with the job of cleansing.

      Think of it like this. Anything you put INTO your body while water fasting is going to interfere with your cleansing metabolism, which is devoted to taking toxins OUT OF your body.

      All the best,

  4. Christina says

    I’ve been reading your blog posts with interest. I have Epstein Barr Virus and have been working on getting rid of it and am making progress, but it’s taking its time. I miss the energy and vitality I used to have. I may have hypoglycemia, don’t know if I still do–if I do it’s not as bad as it used to be. I also used to be pre-diabetic, but am not anymore. I am 54 yrs old, 120 lbs, 5′ 5″. Do you think that 3-day water fasting is something I’d benefit from? I’ve read in the past that those with hypoglycemia shouldn’t fast. What is your opinion?

    Thank you,

    • Tallis Shivantar says

      Hi Christina,

      Thanks for writing. You have two good questions. In terms of dealing with the Epstein Barr Virus (which causes mononucleosis): it’s a tough and stubborn virus, as you’ve already experienced. As much as a 3-day water fast might kill off a flu virus, it’s probably going to have less impact on EBV. Having said that, it may still help to some degree – and that’s certainly better than nothing. What I’d suggest is trying out a 3-day fast and then monitoring your sense of well-being over the next week or so. If you feel a little better afterwards, it might be worth considering a longer fast when you feel ready to do so (perhaps a week or two later). A longer fast will allow your immune system more time and power to attack the virus, with a greater chance of full success. One thing to consider: given the effect of EBV, it’s likely that you’ll feel quite tired during the actual fast, so don’t use this to gauge whether or not your fast is successful. You’ll probably know only afterwards, in retrospect.

      There’s also another factor to consider here. If you don’t already have some experience in water fasting, your body may very well prioritise the lifetime build-up of toxins over attacking the virus. I’ve certainly experienced this myself. In fact, over my first couple of years of fasting, fasts didn’t always have much effect on bacterial and viral illness at all. After I’d reached a point, though, fasting became much more effective in this respect, and nowadays I fast the moment I feel any virus beginning to stir inside me – usually with complete success.

      As far as your other question about hypoglycemia goes: I can’t comment on your particular case, but in my experience there’s a lot of fearful hype around the whole issue. I concur with people like Dr Joel Fuhrman, who writes that hypoglycemia is often a blanket term misapplied and misdiagnosed much, if not most, of the time. I’ve even had people suffering from caffeine withdrawal symptoms swear that they’re suffering from hypoglycemia – despite the fact that symptoms of true hypoglycemia occur at a completely different rate than those of caffeine withdrawal!

      If you’re worried about hypoglycemia during your fast, my advice would be to first try out a shorter 24 hour fast. This is more than enough time to discover how things stand. In the worst case, if you start to feel overcome by symptoms, then you can always break off by sipping a sugary drink – preferably one made from natural sugars, such as orange juice. If you have trouble, then online coaching may be an appropriate solution. (I’ve successfully worked with both Type 1 and Type 2 diabetics.)

      All the best,

  5. Kitin says

    Hi Tallis! Hope you are doing good. I find your post most helpful and informative out of the other blogs/ sites I have come across. Its my second time to do a 3 day fast but I am thinking to do a 5 day fast.. Just would like to ask if is it okay for me to start my fast tom eventhough I have eaten so much this dinner? Thank you.

    • Tallis Shivantar says

      Hi Kitin,

      Thanks for writing and your kind words. Congratulations on going for another 3 day fast – and possibly even making it last for 5 days :-).

      A large last supper isn’t going to kill you, but there IS a difference between a 3 day fast and 5 say fast in terms of how much your digestive system will want to switch off. 3 days really isn’t enough for it to fully go into dormancy, but after 5 days it will have switched off much more fully. This is revealed after the fast. Many people can jump more or less straight back into everyday eating after a 3 day fast (although it’s MUCH better to have a proper period of refeeding instead!). After a 5 day fast, though, most people find that if they return to everyday eating too soon, their digestive system simply can’t cope.

      This is all by way of saying that a large dinner really isn’t the best, especially before a 5 day or longer fast. It will only prevent your digestive system from switching off or may end up just sitting in your intestines for the whole fast.

      All the best,

  6. Ryan says

    Dear Tallis,

    You mention fasting and Multiple Sclerosis, do you have any more information regarding the treatment of MS with fasting? Many thanks, Ryan.

    • Tallis Shivantar says

      Hi Ryan,

      Thanks for writing. Generally speaking, to deal with any serious illness – and especially one which relates to autoimmune issues – it’s usually best to undertake an extended fast lasting several weeks. However, there are always potential caveats which might relate to the individual case, so it’s important not to jump to conclusions here!

      I’ve worked with cases of fibromyalgia/MS myself and have found that fasting does generally help to reduce the severity of symptoms. This can include fasts as short as three days – although such a fast is only going to have a short-term impact on symptoms rather than cause a lasting, long-term improvement in health. Intermittent fasting can also make a difference, especially when combined with dietary change. What I’m saying is that in the worst case there are always options, and there’s never just one possible solution.

      All the best,

  7. Michele says

    How frequently can I do a 3 day water fast? Is once per month or every other month safe?

    Many thanks!

    • Tallis Shivantar says

      Hi Michele,
      Thanks for your question.
      If you’re eating healthily and if you really wanted to, you could do a 3-day fast even every week! In fact, I’m working with someone right now who is doing precisely this for medical reasons.

      So to answer your question, once per month or every other month should be totally safe if you’re otherwise healthy :-).
      The main thing is not to overdo it so that fasting becomes a chore.
      I hope you’ll experience the cleansing and healing of a 3-day fast, and then your body will let you know when it’s time to do another one – whether this is once a month, once every other month or perhaps only once or twice a year to begin with.

      You’ll see,

  8. Franco Catucci says

    Trying again for a three day water fast 72 hour.

    • Tallis Shivantar says

      Good for you, Franco. Good luck!

      • Franco Catucci says

        Tallis whats your opinion of doing a one meal a day , eating every 24 hours and then doing a 36 hour weekly water fast ???

        • Tallis Shivantar says

          Physically this is absolutely fine, so long as you’re eating healthily and keeping your nutrition up. I have clients who follow similar regimes. The only question is whether you find that it becomes a challenge emotionally, because you feel deprived of food. Give it a try if it feels right!

  9. Franco Catucci says

    Hello Mr. Tallis , i set out this weekend to do a 3 day water fast but i only made it to 42 hours i guess it was just the emotional and mental part of my fast so i decided this comiing weekend i am just going to do 36 hour fast for awhile , my ego gets in the sometimes i thought cause I only eat ONE-MEAL-A-DAY OMAD 23-1 that i could easily do a 7 day water fast i only made it to day 3, then i decided to do a 3 day water fast i only made it to 42 hours , so im just going to stick to the 36 hour water fast for a few months before going to a 3 day water fast i am just take baby steps i love the fasting lifestyle . Thank you Mr. Tallis for your WEBSITE its one of the best on the subject of water fasting and i am so inspired by the information you bring and the testimonials on your WEBSITE. God Bless You My Friend sincerely Franco Catucci…..

  10. Thank you!! This article was wonderfully written and full of detailed information to help and allow the reader to truly understand what they are taking on! Thank you so much for sharing!

    • Tallis Shivantar says

      Thanks for your kind words 🙂

  11. Sarvyoga says

    First of all i would like to appreciate your work. Really you have done a fabulous writing work so, that’s why it’s easy to understand.

    • Tallis Shivantar says

      Many thanks for your kind words, Sarvoya. Much appreciated!

  12. Charms says

    Hi Tallis! What would you recommend I take to help eliminate toxins out the body during a 3 – 15 day water fast? Are there any herbal teas that I can drink?

    Thank you

    • Hi Charms,
      Thanks for writing, and sorry for the slow response. I’ve had email problems…
      A water fast – pure and simple with no additives – is all you need :-).
      Especially if you’re fasting for a week or two, that’s already a lot of time for your body to go really deep in eliminating toxins.
      If you feel like drinking herbal teas, that’s fine too. As to which are the best herbs, there’s no single right answer. If you know you have issues with a particular organ, you can drink specific herbs which help to strengthen or cleanse it. There’s plenty of info on the internet about all this, if that’s the route you’d like to go. If you’re generally healthy, though, I wouldn’t worry about herbal teas – unless you want to treat yourself to a little flavour!
      Personally, though, I like the flavour of water 🙂
      All the best,

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