There is no more grueling type of fast or cleansing diet than a pure water fast. A water fast costs nothing to do, and may be used to lose some weight, focus on your inner spiritual life, and possibly help your body flush out toxins.[1] Short-term calorie restriction may help you live a longer, healthier life if done correctly – but fasting can also be dangerous.[2] Whatever your goal, approach water fasting safely – ease into it, work with an experienced healthcare professional, recognize signs of when to stop, and transition back to food slowly.

Part 1
Part 1 of 3:

Planning Your Water Fast

  1. 1
    Do not fast if you have certain medical conditions. Some medical conditions can be worsened by fasting and can lead to serious health consequences. Do not do a water fast if you have any of the following, unless specifically approved by your doctor:[3]
    • Any eating disorder like anorexia or bulimia
    • Low blood sugar (hypoglycemia) or diabetes
    • Enzyme deficiency
    • Late stage kidney or liver disease[4]
    • Alcoholism
    • Thyroid dysfunction
    • AIDS, tuberculosis, or infectious disease
    • Late stage cancer
    • Lupus
    • Vascular disease or poor circulation
    • Heart disease, including heart failure, arrhythmias (especially atrial fibrillation), history of a heart attack, valve problems, or cardiomyopathy
    • Alzheimer’s disease or organic brain syndrome
    • Post-transplant
    • Paralysis
    • Pregnant or breastfeeding
    • Taking medication you cannot stop taking[5]
  2. 2
    Select a length of time to do your water fast. Consider starting with a 1-day water fast. Limit your water fast to 3 days if you’re doing it on your own. Some evidence suggests that just a 1-3 day short-term fast can have health benefits.[6] If you intend to fast longer than that, only do so under medical supervision – such as at a fasting retreat where you’re supervised by a medical professional.[7]
    • It is probably safer and may offer more health benefits to fast for short times periodically, rather than doing a long fast (over 3 days). Consider doing a water fast for one day out of the week at the most.[8]
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  3. 3
    Fast during a low-stress time. Plan your water fast for when you will not be under a lot of stress and when fasting won’t interfere with your daily routine. Whenever possible, avoid working while fasting.[9] Save your fast for a day that you can just rest.[10]
  4. 4
    Prepare mentally. The idea of fasting for multiple days can be daunting. Talk to your doctor, read books on the subject by reputable authors, and converse with others who have fasted. View the fast as an adventure.
  5. 5
    Transition into your fast. Rather than jumping straight in to your water fast, start small. Start to eliminate sugar, processed foods, and caffeine from your diet at least 2-3 days before your fast, and eat mostly fruits and vegetables.[11] Also consider reducing the size of your meals for several weeks leading up to your fast. This can help prepare your body for what’s to come, and make the transition to water mentally easier. Consider using intermittent fasting to lead into your water fast. Such a plan could spread over the course of a month:
    • Week 1: Don’t eat breakfast
    • Week 2: Skip both breakfast and lunch
    • Week 3: Skip breakfast and lunch and decrease your portion for dinner
    • Week 4: Begin your water fast
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Part 2
Part 2 of 3:

Performing Your Fast

  1. 1
    Drink 9-13 glasses of water a day. In general, men should drink around 13 cups of water and other fluids daily (about 3 liters), and women should aim for 9 cups (2.2 liters).[12] You can stick to the daily recommended amount of water during your water fast. Choose the purest water you can, or drink distilled water.[13]
    • Don’t drink all that water at once! Spread out your water consumption throughout the day. Try setting out three 1-liter jugs every day, so you can see how much water you should drink.
    • Don’t drink more water than the recommended amount, as this can throw off the balance of salt and minerals in your body and cause health problems.[14]
    • Drinking enough water while you're fasting is important so you don't get dehydrated.[15]
  2. 2
    Combat bouts of hunger. If you get strong hunger pangs, work through it by drinking 1-2 glasses of water. Then lie down and rest. The craving will usually pass. You can also try distracting yourself by reading or meditating.
  3. 3
    Break your fast slowly and gradually. Break your fast with orange or lemon juice first. Then proceed to add foods to your diet gradually. Eat small amounts about every 2 hours, at first. Proceed in a stepwise process from easily digested foods to foods that are harder to digest. Depending on the length of your fast, you can spread this process out over one day or many days:[16]
    • Fruit juice
    • Vegetable juice
    • Raw fruit and green leafy vegetables
    • Yogurt
    • Vegetable soup and cooked vegetables
    • Cooked grains and beans
    • Milk, dairy, and eggs
    • Meat, fish, and poultry
    • Everything else
  4. 4
    Eat a healthy diet regularly. Fasting won’t help your health much if you return to eating high-fat and high-sugar foods afterwards. Follow a diet high in fruits, vegetables, and whole grains, and low in bad fats and refined sugar. Exercise for 30 minutes five days a week. Live a healthy lifestyle to improve your health and wellbeing, and let fasting be only a small part of that.[17]
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Part 3
Part 3 of 3:

Staying Safe

  1. 1
    Visit your doctor before water fasting. If you’re thinking about doing a water fast, consult your healthcare provider. Though fasting may offer health benefits for some people, others should avoid it. Be sure to discuss your medications and medical conditions with your doctor to determine if water fasting is safe for you.[18] They will likely perform a physical exam and possibly do some blood tests.
    • If you take medication, you will have to discuss with your doctor whether to continue to take your medication while fasting, or if any dose changes need to occur.
  2. 2
    Fast under supervision of a trained professional. It’s best to fast only with a doctor’s supervision and input, especially if you’re fasting over 3 days or have any medical conditions. Find a doctor who is trained in fasting and have them guide you and monitor your condition during the fast. Ask your primary doctor to supervise you or suggest another professional who can.[19]
  3. 3
    Avoid dizziness. After 2-3 days of water fasting you may experience dizziness if you stand up too quickly. Avoid this by getting up slowly and doing some deep breathing before standing.[20] If you do get dizzy, immediately sit or lie down until it passes. You can also try putting your head between your knees.
    • If you become so dizzy that you lose consciousness, stop fasting and see your doctor.
  4. 4
    Differentiate normal from abnormal side effects. It’s not uncommon to feel some dizziness, a little weakness, nausea, or occasional skipped heartbeats while fasting. However, stop fasting and seek medical attention if you lose consciousness, feel confused, have more heart palpitations than one or two a day, have severe stomach discomfort or headache, or any other symptom that feels alarming to you.
  5. 5
    Get plenty of rest during your water fast. You may experience a drop in stamina and energy during this time. Don't overexert yourself. Maintain healthy sleep patterns. Fasting is all about rest - physical, emotional, sensory and physiological.[21]
    • If you feel like napping, nap. Read uplifting material. Listen to your body and don’t push yourself physically.
    • If you feel tired and “out of it,” do not operate a vehicle.
  6. 6
    Avoid intense exercise during this time. Your energy may fluctuate between feeling weak and tired and feeling energetic. Even when you have lots of energy, don’t exert yourself. Instead, try gentle, restorative yoga. Yoga is a calming way of stretching your muscles and getting some light exercise.[22]
    • Yoga and light stretching may feel good to some people, and be too vigorous for others. Listen to your body and only do what feels comfortable.
    • Avoid strenuous activities during your fast since they can put a strain on your body when you're not taking in any calories.[23]
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Warnings

  • Stop your fast and seek medical treatment immediately if you experience severe stomach discomfort, fainting, or confusion.
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  • Water fasts should only be performed by informed adults after consulting with a doctor. It is not suitable for any person under the age of 18.
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  • Don’t get a colon cleanse (enema) before or during your fast. Despite the myth that this is necessary, modern science has found no evidence that it helps, and it may even be detrimental to your health. Enemas can cause cramping, bloating, nausea, and vomiting.[24]
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About This Article

Kristi Major
Co-authored by:
ACE Certified Personal Trainer
This article was co-authored by Kristi Major. Kristi Major is an ACE (American Council on Exercise) certified Personal Trainer based in the San Francisco Bay Area. Kristi has over 18 years of personal training experience and more than 90 hours of recertification study in fitness, health, nutrition, and supplementation. She is CPR and AED certified from the American Heart Association and she has a BA in Television Broadcasting. This article has been viewed 2,220,706 times.
85 votes - 89%
Co-authors: 53
Updated: July 28, 2022
Views: 2,220,706

Medical Disclaimer

The content of this article is not intended to be a substitute for professional medical advice, examination, diagnosis, or treatment. You should always contact your doctor or other qualified healthcare professional before starting, changing, or stopping any kind of health treatment.

Article SummaryX

To successfully perform a water fast, drink 9-13 cups of water spread throughout each day. For your first fast, start with one day of fasting at a time, and never fast for longer than 3 days. If you have strong hunger pains during the fast, drink a glass of water and lie down to rest until the hunger passes. When it’s time to break your fast, drink a small glass of orange or lemon juice, and start slowly by eating small amounts of food every 2 hours. If you’re considering doing a water fast, consult your doctor to confirm that it’s safe for you. For more information on activities to avoid and common side effects during your fast, keep reading!

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