Water Fasting - The Pros and Cons
by Nancy Hearn, CNC

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Water fasting for a day or more can provide significant body detoxification along with other therapeutic benefits.

However, fasting on just water is also one of the most difficult fasts to do, especially during the first three days.

In addition, it is not the best means of body detoxification for everyone and it can even be dangerous for people with major health conditions without proper supervision.

This type of fasting involves drinking only water for one or more days. This means eating no solid food and adding nothing else to the water. 

The idea is to take in zero calories and to keep the body fully hydrated so that the body has what it needs to perform its normal bodily functions and to effectively remove toxins.

It is critical while fasting to drink a minimum of one quart of water, and preferably one-half one’s body weight in ounces of water. 

Thus, if you weight 180 lbs., for example, you would drink at least 90 ounces of water, or about 3 liters.

The length of the fast becomes the key issue and the longer the fast, the more important it is to be well prepared.

If you don’t prepare for even a one-day fast and your body has toxic accumulation, you may experience uncomfortable detoxification symptoms such as headache, nausea, achiness or tiredness.

The best way to prepare for a fast is to eliminate, or at least reduce, caffeine, sugar, white flour, red meat, and processed foods for at least 1 to 3 days before the fast, depending on how long you are fasting.

Even though this preparation is not required, it will minimize the uncomfortable side effects and cravings most people experience during the first few days of a fast.


One of the most significant benefits of fasting is that it gives the body a much needed rest from having to digest food, which takes a considerable amount of energy.

This prolonged rest allows the body then to intensify its normal processes of detoxification and healing.

Most people can do a one-day fast without too much problem. After two to three days of water fasting, the body begins to burn fat as fuel (instead of glucose from the food we eat), and this is when the most benefits can occur. 

After three days on a fast, the body uses sources of protein that are nonessential, such as degenerative tissue, various masses such as fibroids or tumors, and any other foreign proteins in the body such as bacteria, viruses or fungi.

Our bodies are well adapted to survive periods of food deprivation and will thus preserve essential proteins and protect vital organs and muscle tissue for up 30 days.

A few of the most common health benefits experienced after 1 to 3 days of fasting include:

  • Healthier looking skin
  • More energy
  • Reduction of G.I. issues (gas, bloating, irritation, constipation)
  • Decreased cravings for sugar and processed food
  • Enhanced mood

According to Stephen Harrod Buhner, author of The Transformational Power of Fasting, there have been many clinical trials and studies involving people with various health conditions and fasting on water. Just a few of the noted benefits include the following:

  • Reduction in high blood pressure
  • Improvements in symptoms of type II diabetes
  • Weight loss and treatment of obesity
  • Pain relief from joint inflammation issues, including osteoarthritis and rheumatoid arthritis
  • Clearer skin and healing of eczema and psoriasis.


As I already mentioned, fasting on water is difficult for most people because the detoxification process in the body speeds up so quickly and the food cravings can be intense, especially during the first few days.

The fast is also difficult because you are not taking in any calories and thus most people feel tired while fasting on plain water.

The mental and emotional aspects of fasting are often just as difficult as the physical. Many people experience difficult memories or feelings during the fast.

Fasting is more doable if you can be at home and rest when needed. If you have to work while fasting, this can make the fast more difficult. 

Prolonged or repeated fasting has its risks, especially the potential for vitamin deficiencies, blood-sugar issues, and the breakdown of muscle.

Even though short water fasts  (1 to 3 days) are considered safe for most people, some should only do so under the supervision of a health professional who has experience with fasting.

CAUTIONS: Unsupervised water fasting is not recommended for pregnant women, children, people with serious health conditions such as cancer, heart disease or type I diabetes, or kidney disease.

Final Thoughts

When I was in my twenties, I did a one-day water fast almost every week, and it was a great experience.  The one-day fasts got easier and easier, and they left me feeling rested and rejuvenated.

As I got older, I intuitively sensed that water fasting was not as beneficial for me as other types of body detoxification, such as intermittent fasting from meals, a periodic raw vegan diet, and the use of herbal supplements for colon and full body cleansing.

I believe short-term and intermittent water fasting for a meal, for a day, or for a few days will provide many health benefits for most people and give the body a much needed window of opportunity to get rid of excess toxins.

Longer term water fasting (more than 3 days) requires self-education, a well planned fast (including the days before and after), as well as professional support as needed.

Depending on one’s health condition and mental and emotional state while fasting, the fasting experience can also be quite stressful.

Thus, I think one should also weigh the physical benefits of the fast against one’s overall sense of well being both during and after the fast. The negative effects of acute stress does not promote optimal health.



Stephen Harrod Buhner; The Health Benefits of Water Fasting; 2003.

AllAboutFasting.com; “Water Fasting Tips for Success”

Return from Water Fasting to Health Benefits of Drinking Water

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