The Collison Newsletter March 2014

                       FASTING  FOR  HEALTH*   


Definition of Fast/Fasting


To fast:

To abstain from food.

To eat very little or abstain from certain foods.


The act or practice of abstaining from, or eating very little, food.

A period of such abstention or self-denial.



To fast:

To abstain from all or some kinds of food or drink.


Voluntary not eating food for varying lengths of time.



Origin - Old English fæstan - to fast.

Abstinence - The act or practice of refraining from indulging an appetite.


Historical Quotes on the Value of Fasting

  • "Fasting is the greatest remedy - the physician within." (Paracelsus)
  • "Instead of using medicine, better fast today." (Plutarch)
  • "Everyone has a doctor in him; we just have to help him in his work. The natural healing force within each one of us is the greatest force in getting well ...... to eat when you are sick, is to feed your sickness." (Hippocrates)
  • "The best of all medicines is resting and fasting." (Benjamin Franklin)
  • "Nature heals, the doctor helps." (Paracelsus)


Modern Quotes on the Value of Fasting

  • "I believe that fasting is the "missing link" in the Western diet. Fasting is one of the best overall healing methods because it can be applied to so many conditions and people. Fasting is the single greatest healing therapy. It is nature's ancient, universal 'remedy' for many problems. Animals instinctively fast when ill." (Elson Haas, in Staying Healthy with Nutrition)
  • "Due to [the] effects of fasting, a fast can help you heal with greater speed; cleanse your liver, kidneys, and colon; purify your blood; help you lose excess weight and water; flush out toxins; clear the eyes and tongue; and cleanse the breath." (James F. Balch, in Prescription for Nutritional Healing)
  • "Man is the only 'animal' who persists in eating when he is sick, even though he may have no appetite and food makes him nauseous. Fasting is a calming experience. It is restful. It relieves anxiety and tension. It is rarely depressing and it is often downright exhilarating." (Alan Cott, in Fasting: The Ultimate Diet)
  • "The skin becomes more youthful [during fasting]. The eyes clear up and become brighter. One looks younger. The visible rejuvenation in the skin is matched by the manifest evidences of similar but invisible rejuvenescence throughout the body." (Herbert Shelton, in Fasting Can Save Your Life)
  • "Therapeutic [water] fasting accelerates the healing process and allows the body to recover from serious disease in a dramatically short period of time. Fasting with nutritional competence, removes the most significant causes of disease. The job of fasting is to supply the body with the ideal environment to accomplish its work of healing." (Joel Fuhrman, in Fasting and Eating for Health)
  • "The body’s wondrous ability to autolyze (or self-digest) and destroy needless tissue such as fat, tumours, blood vessel plaque, and other nonessential and diseased tissues, while conserving essential tissues, gives the fast the ability to restore physiologic youth to the system. By removing or lessening the burden of diseased tissue, including the fatty tissue narrowing the blood vessels, fasting increases the blood flow and subsequent oxygenation and nutrient delivery to vital organs throughout the body." (Joel Fuhrman, in Fasting and Eating for Health)


Types of Fasting


1)         Dry Fasting


Dry fasting is also called the Absolute Fast, Black Fast and the Hebrew Fast. It is the most extreme type of fasting, and has spiritual roots, and consists of foregoing food and water for short periods. While not necessarily recommended, it has an interesting history.


2)         Liquid Fasting


a)      Water Fasting


Strictly, fasting means eating no food and drinking only water. This is called a "water-fast". More correctly it should be referred to as a "water-only fast" since "water fast" actually means fasting from water rather than on water.


Water fasting is the simplest and perhaps the oldest form of liquid fasting. Purists insist that water fasting is the only true therapeutic fast which delivers the greatest level of therapeutic and maximum self-healing benefits physically and in a short period of time, as detoxification occurs more quickly. It provides the greatest rest for the digestive organs and preserves muscle even while losing weight.


Water fasting is the most challenging fast to perform in the first few days. Careful preparation in the days before a water fast can make it easier, but there is still the emotional challenge. Water fasting is not for everyone, nor is it appropriate at all times.


The ‘how to’ of carrying out a [water] fast is set out in my April 2009 newsletter Raw Juice Therapy - Juice Fasting.


b)     Juice Fasting


Strictly speaking, consuming anything other than water is not fasting. It is a [name of food or liquid consumed] diet. However, the term "juice fasting" is used and is understood to mean that only juice is consumed, all other foods and liquids (except water) are excluded.


The juice fast, also called "juice therapy", is very popular and offers a small amount of nutritional support, in a pure and natural form, during the fasting period.


Different juices are recommended for different conditions. The healing effects of the different fruit juices can be accessed at


For a detailed discussion of this type of fasting, see my April 2009 newsletter Raw Juice Therapy - Juice Fasting. This article sets out full guidelines on how to fast, the length of the fast, and how to break the fast, as well as understanding the withdrawals and healing crises that are part of the detoxification that occurs during the fast. It also lists the health benefits of fasting.


c)      Other Liquids


Following are some of the other liquids that have been popular as “liquid fasts” at various times:

    • The Master Cleanse or lemon diet. This is essentially lemon juice in water with some additional calories from maple syrup. Popular in the 1970's.
    • Raw milk only.
    • Vegetable broth.
    • Various teas, especially green tea and herbal teas. See my September 2007 newsletter A Cup of Tea = a Cup of Good Health.
    • Barley green or wheat grass juice, and other greens such as chlorella.  See my November 2006 newsletter Green Barley Powder.
    • Beer. Historically the Monks in the Middle Ages were known to have fasted on beer. The alcohol intake needs to be monitored! This is not recommended. 

3)         Non Liquid Fasting or Partial Fasting


Again the following are not strictly fasting, but rather food diets, limited to one type of food, or one specific food. They are sometimes called selective fasting. It is not the amount of food, but the exclusion or limitation of certain foods that makes them a partial fast.


a)      Fruit Fasting


A popular form of "fasting" is fruit fasting. In this fast, all foods are excluded except fresh, raw fruits. This is a food fast for beginners, especially the one day fruit fast. A fruit fast, like any of the fasting methods, will create an environment that helps your body to heal.


The flushing out of toxins on a fruit fast is more gentle than occurs in juice fasting, which in turn is more gentle than experienced in water fasting. However, detoxification does take place and symptoms such as headache, nausea, diarrhoea, fatigue, body aches will occur and are considered normal reactions during a fast. These are likely to be most severe on a water fast.


b)     Brown Rice Fast


This is a mono-diet of rice only, all other foods and liquids apart from water are excluded.


Historically, a brown rice fast is actually an ancient practice dating back thousands of years. More recently, this diet dates back to 1939, when Walter Kempner developed the Rice Diet programme at Duke University. It is definitely a milder form of "fasting", the detoxification symptoms being generally quite mild. The macrobiotic diet is mainly rice with some supplements of vegetables. The work of Dr Kempner is detailed in The McDougall Newsletter, volume 12, issue 12.


What Happens When we Fast?


Normally, your body burns carbohydrates, mainly glucose, as fuel. The glucose from food is the fuel for your brain, heart, muscles and most other organs. During a water fast, and less so with other liquid diets, and even less so for non-liquid diets, the body uses the available carbohydrate calories from your last meal. Once these have been used up, the blood glucose levels are maintained to meet the energy needs of the body from the glycogen stored mainly in the liver and muscles. This glycogen comes from excess glucose from the diet which is removed from the blood under the influence of insulin. Once the glycogen stores are depleted, and this happens after a few hours, probably 8-10 hours, your body turns to the fat reserves, which are converted into ketones. These ketones are used as energy sources for the body. The presence of ketones is called ketosis. Mild ketosis, at least in the short term, can be beneficial. It accelerates the loss of fat in the body, it stabilises the body's glycaemic response, and hunger is reduced. When the body is in ketosis, you tend to feel less hungry. Once the glycogen stores have been used up, the body tends to burn up the "rubbish" first before using the fat stores. This is where the process of detoxification takes place.


Thus the purpose and benefit of fasting comes from the detoxification that starts after some 10-12 hours after the last meal.

How Long Should the Fast Last?

This is a very individual thing, and somewhat depends on the type of fast. The following comments apply mainly to water fasting or juice fasting.


A 24 hour fast would be the shortest fast recommended. It meets the above criteria where the body has used up all the glycogen stores and, via gluconeogenesis, is making fuel from waste/toxic matter in the body as well as from fat stores.


The 30-36 hour fast would be the next goal.

  • A 30 hour fast can be achieved by having a substantial lunch and then nothing to eat until dinner the evening of the next day. This is easier that the 36 hour fast since food is consumed each day. Have eaten a good lunch, it is easy to go without dinner that night, and knowing the dinner is coming up the next evening, one can manage not to have breakfast and lunch that day.
  • The 36 hour fast is actually not eating for whole day. Nothing is eaten after dinner the night before, until breakfast on the morning of the day following the fast.

It is recommend that the 24 hour fast is repeated several times, once a week, graduating then to the 30 hour fast and then to the full day 36 hour fast once a week.


After you are comfortable with a regular fast each week, the next step is a 3 day fast.  This can be undertaken without professional supervision and it is quite safe to do. Such a fast would only be carried out periodically, possibly every 3 months. One author suggests having the longer fast with each change of season.


Next would be a 3-5 day fast (longer than 3 days may require supervision). Longer fasts of 7, 10, 14 days or longer must be supervised by a professional experienced with fasting.




There are a limited number of people, particularly patients suffering from certain illnesses, who must not fast except under strict supervision by a professional experienced in fasting. This is not because the fast in itself is unsafe (except in rare circumstances such as malnutrition when there is a danger of it developing into starvation , or when certain drugs are being taken), but because the withdrawal symptoms that may be experienced can be very unpleasant and even harmful.


Those with asthma or epilepsy should exercise special care.


Patients suffering from any condition for which medication is being regularly taken must seek medical advice from the prescribing doctor before starting a fast, particularly to find out whether these drugs should continue to be taken or can safely be omitted. Although we often find that medication can be safely reduced, or left out altogether, nobody should ever take it on themselves to stop taking a prescribed drug.


Diabetic patients, especially those requiring insulin, should only fast under strict supervision of an experienced health practitioner.


Children should never undertake fasting, except under direct supervision by a health professional and, in particular, a water diet lasting for more than 36 hours may be harmful.


Safety of Fasting


In 1987 I published, in the Medical Journal of Australia (vol 147, p152-153), a survey of patients who were critically evaluated from a biochemical point of view during a five-day fast: the results confirmed the safety of short-term fasting.


Breaking the Fast 


After a one day fast, simply return to your normal diet, which should follow the principles set out in my September 2006 newsletter Acid/Alkaline Balance - The ideal Diet and in my March 2009 newsletter Foods for Health.


If you undertake a longer water or juice fast, depending on how long the fast has been, a gradual return to a normal healthy diet (see above newsletters) should take place. Initially add fresh fruit, perhaps some vegetable broth, and then salads and vegetables. After fasting, the stomach has shrunken, and there is little or no appetite (due to ketosis). So the initial meals should be small, gradually increasing in size over a few days.

The Health Benefits of Fasting 

Fasting is said to affect our physical, mental, emotional and spiritual aspects. This is a broad concept. We are much more than a physical body, and fasting affects every part of our being.


The following have been listed as the result of fasting. "Fasting will:

  • rest the digestive system
  • allow for cleansing and detoxification of the body
  • create a break in eating patterns, allowing a review of what should be eaten
  • promote greater mental clarity
  • cleanse and heal "stuck" emotional patterns
  • lead to a feeling of physical lightness, increasing energy level
  • Promote an inner stillness, enhancing spiritual connection."

a)      Physical Benefits of Fasting 

Fasting has been called the "miracle cure" because the list of physical conditions improved by fasting is long and varied. Cited most often are allergies, arthritis, digestive disorders of all kinds, skin conditions, cardiovascular disease, and asthma. Because fasting initiates the body's own healing mechanisms, any ailment may show improvement. Fasting is a wonderful antidote to over-indulgence.


During fasting, we rest our digestive system. Digesting, assimilating and metabolising require a great deal of energy. It is estimated that 65% of the body's energy must be directed to the digestive organs after a heavy meal. Free up this energy, and it can be diverted to healing and recuperation. It can detoxify and repair cells, tissues and organs, eliminating foreign toxins as well as the natural metabolic wastes (which are also toxins) produced by our healthy cells.


Fasting itself is not necessarily a "cure" for anything. What it does is to create the environment in which healing can occur.


Losing weight is, for many, one of the greatest benefits of fasting. Initial weight loss is often significant due to water loss.


Once you have progressed past the stage of dealing with detoxification symptoms, a fast will have you feeling lighter, more energetic, more enthusiastic and requiring less sleep.

b)     Mental and Emotional Benefits of Fasting 

Fasting improves mental clarity and focus. Emotionally, you will feel calmer, clearer and happier. People who fast often report that depression lifts, and goals begin to feel more obtainable as obstacles are put into their proper focus. Some fasters have reported improved concentration, less anxiety, better sleep and waking more refreshed.


Sometimes it is difficult to tell the difference between our emotional and mental aspects, where one begins and the other ends. Am I sad because I have this thought? Or, did I have this thought because I have been feeling sad? Fasting has a way of clarifying these issues.


In other words, when fasting, you see things from a clearer, more appropriate perspective.

c)      Spiritual Benefits of Fasting 

Spiritually, fasting helps us transcend our addiction and attachment to food, and to realise that man does not live by bread alone.  Not only does the mind get clearer, but spiritual awareness deepens. Freed from having to satisfy hunger, one can then turn one's attention to feeding the mind and the spirit. Spiritual masters like Pythagoras would not admit any disciple into the higher teachings unless they had first purified themselves through fasting, often for as long as 40 days.

Intermittent Fasting 

The frequently asked questions "How long should I fast?" and "How often should I fast?" have been addressed above.

In summary, the recommendation for health, disease prevention and longevity is:

  • a weekly fast of between 24 and 36 hours.
  • Longer fasts, for 3, 5, 7, 10, 14 days or longer undertaken less frequently, and, as suggested above, perhaps quarterly with the change of the season.
  • A very long fast in generally a "one off" event.

Intermittent fasting is a pattern of eating that alternates between periods of fasting and non-fasting. The above recommendations are, of course, "intermittent fasting".


Why intermittent fasting?


Intermittent fasting is recommended since there is good evidence that it has beneficial effects on health and longevity of animals, including humans, that are similar to the effects of calorie restriction. These are independent of the benefits of detoxification already referred to.


Scientific study of intermittent fasting in rats, and anecdotally in humans, was carried out at least as early as the 1940's.


The following is a summary of one of the earliest studies in rats published in 1945 in the Journal of Nutrition (31: 363-375) by Anton J. Carlson and Frederick Hoelzel.

"Tests in which a group of thirty-three rats were allowed the same food ad libitum and groups of thirty-seven, thirty-seven and thirty rats were fasted 1 day in 4, 3 and 2, respectively, after the age of 42 days, showed that the apparent life span was increased by the intermittent fasting. The optimum amount of fasting appeared to be fasting 1 day in 3 and this increased the life span of littermate males about 20% and littermate females about 15%. No drastic retardation of growth was produced by the intermittent fasting but the development of mammary tumors was retarded in proportion to the amount of fasting."


A large number of subsequent studies have shown beneficial effects of intermittent fasting in animals.


Studies on humans have shown that intermittent fasting may function as a form of nutritional hormesis. Hormesis is the term for generally favourable biological responses to low exposure to toxins and other stressors. Repetitive mild stress exposure has anti-ageing effects. Exercise is a paradigm in this respect, food restriction likewise.


Other forms of intermittent fasting include:

  • 20 hours of fasting followed by 4 hours of non-fasting (every day) ..."20/4".  This has been called the Warrior Diet. Other variations include "18/6", "16/8". Of these, "20/4" would be the best. It means eating every day, but in a limited window of 4 hours.
  • Fast-5 Diet. This is endorsed by Bert Herring in his book The Fast-5 Diet and the Fast-5 Lifestyle. This is equivalent to "19/5".
  • Alternate-day fasting was shown to be beneficial and similar to calorie restriction in an article published in The American Journal of Clinical Nutrition, 2007, by Krista Varady and Marc Hellerstein.
  • 2 fast days each week. Some recommend that these are consecutive, for example, the weekend. Or the 2 days separated by non-fast days.

The principles have been outlined. It is now up to you, the individual, to select an intermittent fasting regime that you feel comfortable with, and can carry out successfully.


Detoxification is one of the body's most basic automatic functions of eliminating and neutralising toxins through the colon, liver, kidneys, lungs, lymph and skin. The human body can become toxic, or polluted, from foods and fluids that we consume, and from our polluted environment, as well as from the many chemicals that are used on the skin as cosmetics etc. Stress in general can impact upon the body, with toxic end-products.


The body is constantly undergoing detoxification all the time. This is normal physiology. When the toxic load exceeds the natural detoxification process, we become "toxic" with symptoms such as tiredness and fatigue, headaches, altered emotions, lowered immune system, skin conditions and many other problems. When this happens, the elimination organs (colon, liver, kidneys, lungs and skin) need help.


Fasting greatly aids the detoxification process as indicated above. This is in addition to the benefits that are inherent in intermittent fasting as already outlined.


My June 2009 newsletter Detoxification addresses this important subject in detail.


As indicated above, the formation of ketones, leading to ketosis, is part of fasting. This important topic was the subject of my February 2014 newsletter Ketosis - What is It? , and it is recommend this it be read in conjunction with this newsletter. Mild ketosis, at least in the short term of the fasting period, can be beneficial.

Is Fasting Starvation? 

This is another commonly asked question. Many people have equated fasting with starving.


There is a clear difference between fasting and starvation. When we fast, as described in detail above, the body consumes its reserves. Starvation occurs when all the reserves have been used up and depleted and the body is living on vital tissue, primarily muscle. Health is the result of fasting. Death is the end result of starvation.


Fasting is therapeutic.


It is a personal journey.


It is important to listen to your body. If you are considering a prolonged fast, your body will dictate how long you can safely fast. A fast of more than three or possibly five days should be supervised by an experienced health professional.


Despite what the orthodox medical community may feel about the practice of fasting, it is one of the cornerstones for better health.


When animals get sick, they fast (instinctively). Fasting is a natural method of healing.


Understanding the rationale of fasting is the first step, and that is the purpose of this newsletter. Inevitably everything about fasting has not been covered. There are many books devoted to fasting, and a wealth of information is available on the internet for those who want to explore this fascinating subject in greater detail.


The next step requires the discipline and self-control, as well as motivation, to commit to regular fasting of some form.


The outcome is better health and longevity.

"When you go without eating [fasting], don't try to look gloomy as those show-offs do when they go without eating. ... Instead, comb your hair and wash your face. Then others won't know that you are going without eating." Matthew 6: 16-18 (Contemporary English Version). 

There is wisdom in the ancient word. When you decide to fast, one of the biggest obstacles to overcome is the negativity of family and friends. It is often best to do your fast privately, and without fanfare, to protect yourself from such negativity.


"The best of all medicines is resting and fasting."



*Copyright 2014: The Huntly Centre. 

Disclaimer: All material in the website is provided for informational or educational purposes only. Consult a health professional regarding the applicability of any opinions or recommendations expressed herein, with respect to your symptoms or medical condition.





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