The A to Z of Water Fasting

The world of water fasting can be daunting for many, but it’s a shortcut to health, fitness, and freedom for the practicing few. Here’s everything you need to know about the watery way to wellness. 

What is water fasting?

Water fasting is now making waves in the wellness world, with more and more research emerging to back up its claims. A quick scan on the internet will find you loads of loyal advocates who have tried at least short-term water fasting, but what does water fasting mean?

Water fasting means not eating or drinking anything but calorie-free liquids such as water or tea for a specific time. Water fasting has been done for spiritual, health, or medical reasons. Intermittent fasting is a form of water fasting; however, water fast usually refers to prolonged water fasts for 24 – 72 hours.

How long can you water fast?

When most people talk about water fasting, it means prolonged water fasts for 1 -3 days; however, the body is fully capable of going long periods without water. 

Water fasting can be practiced anywhere from 1 day up to 30 days. Therapeutic water fasts can be anywhere from 10 to 14 days or even 30 days, and the longest recorded case of water fasting being 318 days. However, 72 hours of water fasting gives you the maximum benefits, with the least amount of risk and complications. 

Why should you water fast?

Water fasting has been around for thousands of years, primarily for spiritual reasons, and is usually a time for reflection and contemplation for many religions and faith. 

Water fasting is most often done for spiritual reasons and medical reasons such as preparing for a medical procedure; however, water fasting is also an excellent method for increase health: it detoxifies the body, gives the intestinal tract a rest, helps to improve weight loss, and has multiple other health benefits. 

Fasting was already popular during Greek and Roman times. Even in the early 19th century, the knowledge of fasting was widespread, with several books and studies were done on the subject. 

I fast for greater mental and physical efficiency.

Who can water fast?

Most healthy people will have no problem fasting, but it’s not something you should jump into, especially extended water fasting of over 3 days. These longer, therapeutic fasts can be beneficial, but only if you consider yourself a fasting professional.

Certain people should not be fasting at all without medical supervision: 

  • People with chronic diseases — like gout, kidney, and diabetes (both types 1 and 2)
  • People with GERD heartburn or gastroesophageal reflux.
  • Older people — especially over 80
  • Pregnant or breastfeeding women
  • Underweight people 
  • People with eating disorders (or prone to binging) 
  • Children

If you’re part of this demographic, speak to a medical professional if you want to do it. If not, don’t water fast. If you’re not part of this demographic and go into a water fast, ready, and able, it can be a potent tool to reboot your wellness. 

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What happens during a water fast?

The body exists in the fasting state and the fed state when the body flips from sugar burning to fat-burning. 

As explained by George Cahill, an expert in fasting physiology, and Dr. Jason Fung, leading fasting doctor, specific hormonal changes happen during these stages. 

Feeding stage: When your body is in the fed state, blood sugar increases, and insulin gets secreted into the bloodstream, which then ushers glucose into the cells to give it energy. Excess glucose gets saved into the liver or the muscle cells; when the storage space for glycogen is full, excess glucose is converted into fat. 

Post-absorptive stage ( 24 -36 hours fasting): blood sugar and insulin have fallen, the liver starts to break down glycogen and release glucose. Glycogen lasts for 24 to 36 hours. 

Gluconeogenesis stage (24 – 48 hours fasting): Glycogen stores run out, gluconeogenesis starts in the liver, as new glucose is made from amino acids. Glucose levels fall, but stay in the normal range. 

Ketosis stage ( 48 – 72 hours / 2-3 days fasting): Insulin drop triggers fat breakdown (Lipolysis). Triglycerides in your fat cells get broken into fatty acids and glycerol. Glycerol starts making glucose, and gluconeogenesis stops. Fatty acids get used by most of the body’s cells; some fatty acids become ketones for the brain. More than 75% of the brain energy comes from ketones after 4 days of fasting. 

Protein-conservation stage( 120 hours / 5 days fasting): Increased human growth hormone levels preserve muscle mass and lean tissue, average protein turnover—but not used for energy. Your body is in full ketosis, and ketones and fatty acids supply power. Blood glucose is provided by glycerol. Adrenaline increases metabolism, so you’ll have plenty of energy. 

Your body’s fat-burning metabolism continues from this point on, and you can keep using ketones for energy for as long as you have fat on your body. Your body will use fat as its primary energy source, up to 4% of body fat.

Your body stores about 200,000 calories from fat; a single pound of fat contains about 3500 calories, and according to Dr. Seigei Filanov, can be metabolized for 2 -3 days. Meanwhile, one days’ meal has 2000 calories. Just think about that before your next marathon! 

Benefits of water fasting

Whenever you’re feeding, the body directs 80% of its energy towards digestion. When you’re fasting, the body directs 80% of its energy towards healing. That’s why intermittent fasting is an excellent idea— because instead of spending 1/3 of our day (8 hours) in 80/20 towards health, you’re spending 2/3 (16 hours) of your time towards health. It’s just good ROI.

So with that in mind, let’s take a look at the big list of benefits from water fasting. Here are a few backed by research: 

Promotes autophagy 

Autophagy is a cellular recycling system that keeps your body younger and better functional by breaking down or consuming cells and tissues that are not needed, damaged, or unhealthy. Animal studies show that autophagy can prevent cancerAlzheimer’s, and heart disease. 

Helps reduce blood pressure 

Longer water fast has been shown to help reduce high blood pressure. These are usually medically supervised water fasts of about 14 days. High blood pressure is typically the result of high fluids and salts in the body, caused by poor insulin sensitivity. Fasting improves insulin sensitivity, which regulates blood pressure. 

Improves insulin and blood sugar 

Evidence on water fasting shows that fasting helps with insulin control and diabetes treatment and prevention. Insulin regulates your blood sugar, which is what causes diabetes. One study researched people with diabetes for 3 months, who all did 24-hour water fast once a week, and within 3 weeks, all the participants could stop taking insulin to control diabetes and lose weight. 

Lowers risk of chronic diseases

Studies show that water fasting can lower the risk of age-related chronic diseases like cancer and heart disease. These studies done on animals show that water fasting can protect the heart from free radicals. Free radicals are a major cause of chronic diseases. 

Fights inflammation 

Inflammation is a primary reason for more chronic diseases, especially chronic inflammation. Although inflammation is a good thing used to fight off disease, chronic inflammation can be the single cause of most chronic diseases such as cancer, multiple sclerosis, and heart disease.

Aids weight loss 

Weight loss is a major reason why people do water fasting. A reduction in calories results in increased weight loss, as your body will burn fat. One review of intermittent fasting( 3–12 weeks) resulted in weight loss of decreased body weight of 8% and fat mass of 16%. Studies also show fasting is far more effective than caloric restriction at increasing fat loss because it also preserves muscle tissue. 

Short-term fasting has been proven to increase your metabolism because it increases the secretion of norepinephrine, which increases weight loss. Increased metabolism will naturally boost weight loss over the long term, as you’ll need more energy. 

Increases human growth hormone 

Human growth hormone (HGH) is often thought of as the serum of youth, with many people, especially athletes and the aging, taking tablets or artificial injections to get more. HGH is vital for growth, metabolism, muscle strength, and weight loss.

Fasting naturally increases HGH levels, which is also the result of norepinephrine secretion.

This study shows fasting for 24 hours increases HGH significantly, while this study on men shows HGH levels increased 5 times, just after 2 days. 

Delays ageing 

Fasting can delay aging, and you might notice many people who have fasted for years look a lot younger than they are.

Fasting can extend life by possibly 30% more. This study on rats that fasted every other day had a delayed rate of aging and lived much longer (83%) as opposed to unfasted rats. 

Risks of water fasting 

Even though there are many benefits to water fasting, you should also be wary of the potential problems. Here are a few to keep in mind. 

Refeeding syndrome 

Overeating too soon, especially after a longer fast, can cause the refeeding syndrome. It’s a potentially fatal condition caused by a sudden shift in the electrolytes in your body. 

Although it is pretty rare, the refeeding syndrome can happen to anyone. Still, you’re at higher risk if you suffer from cancer, anorexia, drink a lot of alcohol, have difficulty swallowing, or are generally malnourished. You shouldn’t be water fasting in most of these cases anyway, or only under medical supervision.

Refeeding syndrome happens when you start eating again. Your body shifts from fat metabolism to carbohydrate metabolism and insulin increases, but your body doesn’t have enough electrolytes, like phosphate, to carry out its normal functions.

Symptoms of refeeding syndrome include fatigue, confusion, inability to breathe, seizures, heart arrhythmia, heart failure, coma, and death. If you’re doing a fast of over three days, be extra careful, and take all precautions. 

Nutrient deficiencies

By restricting calories, you’re stopping your body from many essential foods it needs to function at its best — electrolytes, amino acids, fatty acids, vitamins, and minerals. If you’re not in good health or have any underlying health conditions, make sure you speak to a medical professional before water fasting for an extended time, especially over 24 hours. 

One simple way is to add 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 it gives your body all it needs and keeps you in keto!


At least 20% of the water you get daily comes from your food. When you cut out food, you take less water, so the idea is to compensate for this loss of water intake from food by drinking more during a water fast.

Although the amount of water you need to drink is debatable, as mentioned before, do always keep an eye out for the color of your pee, and always drink when you’re thirsty. These are some signs of mild dehydration: 

  • Constipation
  • Feeling tired or lethargic 
  • Increased thirst 
  • Dry mouth, lips, and eyes
  • Headaches
  • Bad breath 
  • Dizziness or lightheaded 
  • Dry skin 
  • Decreased urination 

These are the symptoms of severe dehydration: 

  • Rapid breathing 
  • Lack of sweat 
  • Shriveled skin 
  • Extreme thirst
  • Low blood pressure 
  • Rapid heart rate 
  • Dark, strong-smelling pee

Some weakness or headaches might happen if you’re new to fasting, but if you start showing any of the signs of severe dehydration, get medical attention.

Blood pressure changes

Drinking too much water during water fasting is not a good idea because it might lead to hypotension and extremely low blood pressure — the opposite of hypertension. Hypotension can cause dizziness, lightheadedness, blackouts, or fainting; this can also happen when suddenly standing. 


When you exercise or sweat too much during water fasting and don’t replace the salts lost, you get hyponatremia (also known as water intoxication).

You shouldn’t exercise too much during a water fast, but if you are exercising, make sure you take your daily dose of minerals — phosphate, magnesium, and sodium in the amounts recommended. Even a teaspoon of Himalayan Rock Salt or Sea salt will help avoid problems from electrolyte imbalance and give you more energy in general. 

Dizziness, fatigue, and trouble focusing

Calorie restriction can cause fatigue, weakness, and lethargy. Sometimes you can also get headaches or have poor focus, which carb cravings, or caffeine withdrawals can cause. 

If you’re not used to fasting yet, these symptoms might be more likely —which is why when it comes to fasting, you must practice, practice, practice. Once your body is used to fasting, many advanced fasting practitioners report increased clarity and focus during water fasting. 

Disordered eating

If you’re prone to binge eating, emotional eating, or having an eating disorder, you’re more at risk of binging after water fasting. As anyone who’s water fasted for a few days, and they’ll tell you when you’re fasting, you’ll likely be spending hours obsessing over food. If you binge the moment you end a fast, you risk spoiling all the healthy benefits you earned from it simply because you overate or ate unhealthily. 

This is also why it’s vital to plan when you break your fast, what you eat for the day you break your fast, and days after the fast. Fasting does not stop when you stop the fast, it stops after the refeeding, which can be several days after. 

Feeding after a fast is vital to the health benefits of the fast since your body craves salt and carbs and any nutrient intake. You become also prone to excessive weight gain if you binge eat after a fast, and insulin is very sensitive and quickly stores excess fat. 

Of course, if you like water fasting, you should definitely try dry fasting! For more on how to fast for age reversal and weight loss, check out my video course, 25 Again! The Dry Fasting Lifestyle For A Younger, Slimmer You


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***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 in this article. THE USE OR RELIANCE OF ANY OF THE INFORMATION ON THIS WEBSITE IS SOLELY AT YOUR OWN RISK.***


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