If you’ve ever tried a water fast and then never did it again, it’s likely you did it wrong. Water fasting can be utterly rewarding, but preparation, practice, and exit are everything to getting it right!
Water fasting means no food at all, only water or certain liquids. Intermittent fasting (IF) is a form of water fasting, usually done for 12-18 hours. Water fasting usually refers to abstaining from all foods for 24 -72 hours, although some therapeutic water fasts can go up to 30 days.
The proper way to do a water fast is to prepare for a water fast in advance, drink suitable liquids depending on the reason for your water fasting, and break your water fast with appropriate nutrition carefully.
How to prepare for a water fast
Plan ahead for your water fast. You should already think of when you will break your fast, how and what you will break it with, what day and time you will end it. So you stick to your designed plan and make it to the finish line, but also you don’t push yourself too far, and only increase it incrementally, intuitively checking how you feel, which leads me to the next point.
Before starting water fasting, you should try other types of fasting to build up your fasting practice. If you’re new to fasting, you might not be prepared to do a 72-hour water fast; your body might not be ready for it.
There are many kinds of fasting:
- Intermittent Fasting (IF): World’s most popular method of water fasting, and is mostly practised for 16:8 ( fast for 16 hours, eat for 8 hours), although many also do 18:6 or 20:4.
- Intermittent Dry Fasting (IDF): The same as intermittent water fasting, except done without water. Usually between 12 – 20 hours.
- Dry Fasting (DF): Fasting without food or water, usually done for 24 hours, sometimes 36 hours. More intense but 3 times as efficient as water fasting for health & weight loss results.
- Juice fasting: Only drinking vegetable or fruit juices. Usually for 3- 5 days or a week.
- 5:2 Fasting/ Diet : Eating normally for 5 days of a week and eating less than 500 calories for 2 non-consecutive days.
- Alternate day fasting: Fasting one day and eating the next day. It can be done with 24-hour fasting or 36 hour fasting periods.
- OMAD: stands for One Meal A Day, which usually means you fast for 22-23 hours and eat within an hour.
Intermittent fasting is a good entry point to more extended periods of fasting. Start small, skip breakfast every day, and eat an early dinner; you’ll quickly start to appreciate the lightness you feel when you’re not stuffing your face and day and night. Just doing intermittent fasting will highlight your body’s relationship with food.
Once you’ve tried IF, you could mix up a combination of these, and once you feel more comfortable, doing a 3-day water fast won’t seem so daunting.
Fasting is both a physical, emotional, and physical exercise. Although the benefits are proven, many people will tell you that fasting is scary, or that it’s bad for you, or ask you why starve yourself?
Reading up on information will help you understand what goes on in your body during a water fast and better adapt to it. If you’re hungry, that might be because you ate certain types of foods before fasting or didn’t get enough sleep, so read up! As you find out more information and practice different types and fasting, you’ll begin to experience the results for yourself and appreciate the benefits first hand.
Before you do a water fast, also prepare your body by having smaller meals; this will also help you get used to water fasting, as your stomach will shrink after fasting and crave less if you haven’t been gorging all the time.
Eating clean before the water fast, such as more raw foods, including vegetables, fruits, and healthy fats, will also make sure you’re not having sugar cravings from the lowered insulin in your body.
Also avoid heavy carbohydrate meals before fasting, as it will make you hungrier later on, or even the next day.
Having a small portion of a high-fat meal as your last meal and a half portion is the best food prep, this gets you into ketosis quicker, which gives you more health benefits for the body.
How to do a water fast
Stop eating for 24-72 hours. Keep yourself busy or productive with work or engaging material. Water fasting is usually quite manageable in terms of weakness, so it’s primarily occasional hunger.
Do the water fast following the circadian rhythm, meaning it’s best to be fasting while you sleep, or when its night time, and break your fast in the morning, as that’s when you’ll get the best results and benefit from all the healing hormonal changes during sleep.
If you’re healthy, trained, and taken precautions, hunger is really the only issue for a longer fast. You might feel hungry at mealtimes, which isn’t even real hunger, but since your stomach usually has food during those hours, it grumbles. Most of the time, hunger disappears after 36 hours—and from that point on, it’s just cruising. If you do feel hungry, have a hot drink, it helps.
If you’re starting out on long water fast, stay away from kitchens, or restaurants, or anywhere with food or the smell of food. You have basic animal instincts with prehistoric senses, so even the smell and sight of food can trigger hunger.
Eating begins with the nose and eyes, which is why restaurants spend time making food look good. Once you’re advanced faster, the self-control (and lack of desire) comes naturally, and being around food environments won’t be an issue—you’ll love that purr in your belly!
You’ll also find yourself looking at food porn online during your water fast, or checking out menus of what you can eat once you break your fast, so be sure to plan your refeeding meals, so you don’t sabotage yourself which we’ll get into shortly.
If you exercise during the water fast, don’t do anaerobic exercise, such as long-distance running. Instead, do resistance training exercises, such as yoga and weight lifting, as you can benefit from your high human growth hormone levels to protect your muscles. When you break your fast, make sure you eat proteins for muscle growth—eggs are great for leucine content.
Most sources say you should drink about 3 liters a day. The idea is you’ll need extra water, since you’re not getting water from food, you might get dehydrated. This is debatable, however, and as long as you enter the fast properly hydrated, meaning your pee should be clear and light-colored, you’ll be alright. The best is to drink when thirsty.
What can you drink during a water fast? This question is also has mixed reviews. The purists say only drink water for the entire duration, and if you are doing a water fast for medical reasons, you should stick to that.
If you’re doing water fasting for general health reasons, for a digestive break, or weight loss, then you can have anything under 20 calories, and it won’t break your fast.
Some of the options on a water fast include:
- Green tea
- Black tea
- Fruit & Herbal Teas
- Coffee without milk
- Water with Apple Cider Vinegar
- Water with a squeeze of lemon
- Bone broths
These options also depend on why you’re doing the fast. If you’re looking to gain on autophagy, then having bone broth will stop autophagy—as even a little protein will stop the internal processes. If you want to heal your digestive system and prevent any secretion of hydrochloric acid, then avoid apple cider vinegar.
You should also take minerals during the water fast, sodium is the most important, and magnesium and potassium as well. Take half a teaspoon of salt when fasting over the entire day. You can make a glass of water with this amount and drink it four times a day to get your dose. This protocol is more important if you’re doing a water fast over 36 hours or if you’re exercising.
How to break a water fast
Breaking your fast is almost as important as the fast, as your body needs nutrition, but is sensitive, so we need to treat it gently. The first meal after water fasting should be a small-sized portion, eat something less than the size of your fist, or what fits a teacup, and less than 500 calories in your first meal. Don’t binge! Your body has also slowed down its digestion, so your stomach has shrunk, and if you binge, you could feel very uncomfortable and possibly ill.
How you break your fast does depend on the length of your fast. With a 16-hour fast, you can be less fussy, but be extra careful after a 72 hour fast. This is also to avoid refeeding syndrome, which is potentially fatal. If you’ve fasted for 3 days, it might take at least 3 days to start eating normal-sized meals.
The common wisdom is that refeeding after a fast should take twice the length of the fast. If you fasted for 72 hours (3 days), you should be refeeding for 146 hours (6 days). What you eat after the fast is also important because of the changing electrocyte balance in your body. You can be prone to insulin spikes and water retention.
You should eat light, healthy, easy-to-digest foods when breaking your fast. Good options include a handful of nuts, a small salad with olive oil, avocado, a bowl of miso soup, bone broth, or fish broth. You can also eat probiotic and prebiotic foods to repopulate your gut biome with good bacteria.
A sample break fast for different durations:
Break 1-Day water fast (24 hours)
- 8 AM – Water with apple cider vinegar (ACV)
- 9 AM – Handful of almonds or nuts
- 12 PM – Omelette & avocado
- 4 PM – Yogurt & berries
- 7 PM – Chicken/ fish & kimchi/ sauerkraut
Break 2-Day water fast (36 – 48 hours)
- 8 AM – Water with ACV/ probiotics
- 11 AM – Miso soup with seaweed/ bone broth/ fish broth
- 1 PM – Eggs & cucumber tomatoes salad/ sauerkraut
- 5 PM – Handful of nuts & kefir
- 7 PM – Fish / tofu & vegetables
Break 3-Day water fast ( or follow protocol 1-Day Dry Fast)
- 8 AM – Water with probiotics
- 11 AM – Miso soup/bone broth/ fish broth
- 12 PM – Eggs & kimchi
- 3 PM – Handful of nuts.
- 5 PM – Avocado & nutritional yeast & seeds
- 7 PM – Yogurt
This article by the dietdoctor.com gives some examples of other foods to break your longer water fast and some useful information too.
For supplements, I recommend the Fruit Fusion multivitamin and mineral powder. It’s used for breaking advanced and long term fasting or can be used daily, so will highly benefit water fast as well, giving your body all it needs and keeps you in keto!
Flushing your body with water is not necessarily the purpose of water fasting. Water fasting is a fast where you drink water to remove toxins, but it’s not necessary to drink bottles and bottles of water.
In the absence of food, your body considers water as food, so drinking loads of water might not helping your body. Your body considers water a food source, but it’s a highly nutrient-deficient food source. Most of the water we drink is contaminated as well, ‘dead’ water. Humans should be drinking pure spring water.
Dr Jason Fung, a fasting expert, suggests drinking two liters of water daily and starting each day with 250 ml (8 ounces of water), or one glass, which is a good guide to start with.
However, nowhere does it say that 8 glasses a day is necessary for the human body to survive. In 2002, a review in the American Journal of Physiology, “Drink at least eight glasses of water a day. Really? Is there scientific evidence for “8 × 8”? was published, studied over 100 articles, and did not find evidence of this to be true.
Dr. Herbert Sheldon, who has written several books on fasting at the turn of the century, and uses research from the early 1900s, defines fasting as total abstinence from all food, with only small sips of water taken from time to time, when desired. Much of the studies have been on animals, and animals only drink according to need.
Drinking too much water also doesn’t help if weight loss is the goal of your water fast, as water clogs up your fat cells and doesn’t facilitate weight loss as easily.
The best you can do for your water fast is to make sure the water you’re drinking is the best quality water you can get, and the golden rule to know you’re drinking enough is to make sure your pee is clear. That way you’ll know you’re well hydrated, whatever the case might be.
For more on how to water fast and dry fast for age reversal and weight loss, check out my video course, 25 Again! The Dry Fasting Lifestyle For A Younger, Slimmer You.
***Disclaimer: I am not a doctor/ physician, and although I have a bachelor’s degree in Biomedical Science, I cannot and do not hold myself to be a medical professional (“Medical Provider”). This article does not contain medical /health advice. The medical/ health information here is for general and educational purposes only. It is my opinion, based on my research and personal experience, and not a substitute for professional advice by your health care provider. Please consult with a professional before acting on the information here, and do not disregard medical advice or delay seeking medical attention because of anything you read on this article. THE USE OR RELIANCE OF ANY OF THE INFORMATION ON THIS WEBSITE IS SOLELY AT YOUR OWN RISK.***
- Fung, Jason, and Jimmy Moore. The Complete Guide to FASTING: Heal Your Body Through Intermittent, Alternate-Day, and Extended Fasting. Victory Belt Publishing, 2016.
- Longo VD, Panda S. Fasting, Circadian Rhythms, and Time-Restricted Feeding in Healthy Lifespan. Cell Metab. 2016;23(6):1048-1059. doi:10.1016/j.cmet.2016.06.001
- Valtin H. “Drink at least eight glasses of water a day.” Really? Is there scientific evidence for “8 x 8”?. Am J Physiol Regul Integr Comp Physiol. 2002;283(5):R993-R1004. doi:10.1152/ajpregu.00365.2002