The Traditional Christian Fast

Perspectives from the Saints, History and Medical Science

by Fred Krueger

Santa Rosa, California

Fasting has always been a pillar of spiritual formation in the Church of Christ. It builds discipline, restraint and cultivates obedience to Church guidance. Anciently the Christian fast was a total fast. No solid food was taken.

Over the centuries, a moderating influence entered parish life. Health and strength issues required special treatment and dispensations became normal for a variety of personal situations. At the same time, as Orthodox converged on America from European countries, they brought different assumptions about fasting. Archimandrite Akakios at the St. Gregory Palamas Monastery in Etna, California, describes some of the problems with establishing a common rule for fasting in America.

The limited instances where fasting is practiced in modernist American Orthodox jurisdictions are beset by confusion and innovation…. Many of the Orthodox immigrants who came from the Old World failed to preserve their fasting routines in a land where new foods and new menus changed their way of life. Many came with an improper understanding of fasting to begin with…. The spirit of reform embraced by the calendar change… included specific proposals for the relaxation of fasting rules. Brought to the Americas by immigrants — some of them coming as Hierarchs to serve the Church — this revisionist spirit deeply affected the Orthodox population here. The Eastern European [Uniate] Catholics who converted to Orthodoxy in America came from a spiritual milieu in which fasting neither took the same form nor had the same theological significance as it does in the Orthodox Church. And the national Slavic Churches in the emigration also understood asceticism from a far more Western than Orthodox perspective. So it is that the ethnic Orthodox Churches saw the birth of “relaxed fasts” and “moderate” fasting rules…. All of this they passed on to a new generation of Orthodox and to converts…. Wholly unfamiliar with Orthodox fasting traditions, many Orthodox today have taken these contrived notions in the immigrant Churches as authentic practices and have come to treat them as part and parcel of Church teaching.

The current Orthodox fast as practiced in America is intertwined with the religious reforms that arose in Russia around the time of Tsar Peter the Great (1672-1725). Prior to his era, fasting was far stricter and considered essential for spiritual growth. The consequence is that our modern fasting rules are largely an abstinence from heavy foods. This change explains why we no longer claim that the “fast” transforms, because by itself it does not. In our era, when we fast, we mostly become vegetarians for certain times of the year.

During the time when fasting rules were being relaxed, the Archbishop of Constantinople +Ecumenical Patriach Nicephorus Theotokis (1731-1800) wrote the following about the new rules:

When we fast, we search the earth and sea up and down: the earth to collect seeds, fruits, spices, and every other edible thing; the sea to find shellfish, mollusks, sea urchins, and anything edible therein. We prepare dry foods, salted foods, pickled foods, and sweet foods, and concoct many different dishes, seasoned with oil, sweeteners and spices. Then we fill the table even more than when we are eating meat. And yet we imagine that we are still fasting…. Whoever taught… that such a variety and such quantities of food constitutes a fast? Where did they hear that anyone who simply avoids meats or fish is fasting, even if he eats a great amount and different kinds of food? Fasting is one thing, a great variety in food is another. Fasting is one thing, eating great  amounts of food another.

Prior to the 18th century, strict fasting was essential for Orthodox Christians. Listen to what Saint Nikodemos the Hagiorite writes about fasting:

Canon 69 of the Holy Apostles declares that any hierarch, priest, deacon, subdeacon or reader… who does not fast during Great Lent and on Wednesday and Friday is to be deposed. If a layperson does not fast during these times (unless he cannot on account of illness), he is to be excommunicated.

To our modern thinking, the severity in this earlier rule seems shocking. Rather than criticize the old rule’s strictness or defend our modern dispensations, let’s review the implications of fasting. By subjecting the fasting rule to modern medical research, perhaps we can bring into focus some of the basic benefits that accompany fasting. To structure this examination, I will present simple conclusions about fasting from three perspectives: its effects on human physiology and functioning of the body, on the psychological state of our minds, and finally on our spiritual lives.

The physiological effects of fasting are many. When the body goes without food, medical research reports that a series of important physical changes occur. Initially, the digestive tract receives a rest. During this rest, the body uses its energies to increase its autolytic (or self-healing) actions. The body’s energies are then used to repair and restore bodily functions. In contrast, with a steady supply of nourishment, the systems of the body continually work to process food and maintain the system. Without rest, the body wears down over time. In those over thirty years of age, this causes a gradual, but steady buildup of toxins, plaque, and deposits which gradually stiffen and clog the system. This happens because a continual stream of food produces a continual accumulation of waste. In contrast, on a genuine no food fast day (i.e., the original Christian fast), the autolytic functions work from deep down at the cellular level of the body and perform a long series of “house-cleaning” functions so that a rejuvenation and mini-healing occurs. During these times the body uses its energies to attack and remove disease formations, tumors, or any unnatural growth in its system.  

Fasting provides more than rest to the assimilative organs. A cleansing also takes place. Body wastes and toxins are eliminated from the digestive and circulatory systems which freshen circulatory functions. It removes disease in its formative stage, including cardiovascular and circulatory diseases, diseases of the digestive system, and the locomotor system – including rheumatism, respiratory diseases and asthma, etc. At the same time a strengthening of the immune system occurs.

Research at the University of California at San Francisco’s School of Medicine finds other health benefits. These include a sharply reduced risk of cancer (because the autolytic process attacks and dissolves tumors at the stage of their formation as well as other abnormal pre-cancerous growths). The autolysis causes a slowing of the aging process. Several different studies show that the only proven method for improving health and increasing lifespan is to reduce caloric intake. According to Dr. Mark Mattson, chief of neurosciences at the National Institute on Aging, “fasting shows more ability to provide beneficial qualities to the older body” than any drug or medication.

The National Academy of Sciences cites additional benefits of stress reduction, increased insulin sensitivity and reduced morbidity.

Fasting is also highly beneficial to digestion health. When you are not eating, a different set of microbes emerges and cleans up your gut wall, processing the sugars which is important for maintain immune balance.

Besides the revitalization of digestive organs, the additional physiological benefits include clearer skin, improved hearing and taste, reduction of allergies, weight loss, drug detoxification, and heightened disease resistance. Fasting clears out problems from overeating and a sedentary lifestyle. No wonder so many of the desert fathers lived past 100 years of age! These physical benefits derive from genuine fasting, but most importantly they do not derive from merely an abstinence from meat and heavy foods. Generally what is happening physically reflects what is taking place psychically and spiritually.

Next a set of psychological and psychic benefits emerge from fasting. During a fast the mind develops clarity and the will is strengthened – because it is exercised through the denial of the desire to eat. Something fascinating now happens. True fasting (i.e., water only) causes a cautionary attitude to arise so that one is careful not to break the fast. Fasting then becomes a cornerstone for a life of restraint and thoughtfulness. This happens because fasting from all forms of food and nutrition stretches out and addresses the tendency toward consumerism and materialism. Fasting thus witnesses to the conflict between the indulgences cherished by the modern mentality and the ascetic life of the Church. An important implication is that traditional spiritual formation cannot be attained without old style fasting.

As the will is strengthened, the person who fasts increases in self-control. At the same time fasting results in a heightened sensitivity to others – because feelings become far more sensitive and acute. This causes those who fast to sense the plight of poor people. In this way alms-giving is connected to fasting because without fasting, we scarcely cultivate the sensitivities of the heart that foster compassion for those who have little.

On a longer fast – over more than a day, the body begins to stimulate the production of the hormone serotonin to insulate itself from the pangs of hunger. The initial day of fasting may at first be difficult, but the morning of the second day can be quite enjoyable because serotonin creates a distinct feeling of euphoria. The person who fasts will feel alert, active and often even excited to continue fasting. Studies show that most people who follow the original fasting rule report heightened mental clarity, a more positive mental outlook, and emotional serenity when embracing traditional fasting rules.

A regular pattern of once a week fasting produces an optimistic outlook on life as well as an overall feeling of purity, cleanliness and self-control. A conclusion from medical studies is that fasting can be enjoyable and healthy.

Medical studies on the spiritual side of fasting are elusive because science is not effective in probing into this aspect of life. Nevertheless we discern deeper implications to fasting when Jesus tells the apostles (after they  ask him why they could not heal the boy possessed with a demon) “…this kind does not go out except by prayer and fasting” (Matthew 17:15-21).

When the physical body is regularly cleansed by fasting, an additional result is that psychic and spiritual impressions become stronger and more frequent. One’s energy becomes more refined. The world may even appear transparent. At this time prayers have a higher and more uplifted quality. One’s whole being experiences a sense that the etheric and spiritual worlds intertwine and are drawing closer together. Sleep is deeper and more fulfilling. The saints frequently write that visions and holy experiences are more readily attained during times of fasting.

The enhanced sensitivities that accompany a fast open a realization that the fast cannot be restricted merely to a denial of meat and other heavy foods, but it must include a denial of negative thoughts, anger and all of the passionate tendencies. This is why Saint Basil writes, “there is a physical fast, but alongside it there is also a spiritual fast.” He continues:

In the physical fast the body abstains from food. In the spiritual fast, the faster abstains from evil intentions, words and deeds. One who truly fasts abstains from anger, rage, malice and vengeance. One who truly fasts abstains from idle and foul talk, gossip, condemnation, flattery, lying and all manner of spiteful talk. In a word, a real faster withdraws from all evil…. As much as you subtract from the body, so much will you add to the strength of the soul.

Saint John Chrysostom makes a similar observation.

“It is necessary for one who is fasting to curb anger, to accustom himself to condescension, to have a contrite heart, to repulse impure thoughts and desires, and to reflect on what good has been done by us in this or any other week, and which deficiency we have corrected in ourselves. This is true fasting.”

As for those who worry that fasting might harm their health, they need only recall the longevity of the saints who cultivated fasting as a way of life. Denial of food for them was the doorway to health and vitality.

 Saint Alypius the Stylite lived for 118 years; Saint Anthony the Great – 105; Saint Theodosius the Great – 105; Saint Paul of Thebes – 113; Saint Paul of Komel – 112; Saint Cyril the Anchorite – 108; Saint Kevin of Glendalough – 105.

This list is only a short beginning. These saints did not require special foods, vitamins or nutritional supplements to live long inspired and productive lives.

While our present fasting rules carry some benefit, we should recognize that they only scratch the surface of the potential latent in fasting to bring healing and transformation.

As Archbishop Nicephorus wrote several centuries ago, “fasting is one thing, but eating a great variety of vegetables and seeds is another thing entirely,” but it should not be called fasting. As we examine the many dimensions to fasting, we should recognize that a recovery of this ancient practice is necessary if we are also going to recover our rightful heritage of spiritual experiences and attainment.

For those individuals who might wish to start fasting in the traditional manner, here are a few guidelines.

Drink at least seven or eight full glasses of water during the fast day. This is because – at least in our western diet – so many toxins are released during the fast and the water helps to flush them out. Think of the task this way: “The solution to the body’s internal pollution is dilution.”

For those who are habitually champion meat eaters, there can be an acid buildup – the result of too many fats and toxins which are released during the fast. This can show up as a slight stomach ache. Address this by adding a  teaspoon of baking soda in a glass of water. This neutralizes the acid which is being cleansed out of the body into the stomach. This is usually experienced by first time or new fasters.

A headache may also occur at first and these are symptoms of psychological resistance to the fast. Those who possess obsessive-compulsive eating disorders usually have layers of issues and so they need a firm rule that holds them to guidelines – one day of fasting per week and no more.

A full day of fasting can begin after the evening meal on Tuesday, continue all through Wednesday and conclude at breakfast on Thursday. By following this simple rule every week, the traditional benefits of fasting can return in your experience.

Basically fasting is like a muscle. The more you practice it, the easier it becomes to fast. After several months of once a week fasting, your body becomes so adjusted to the fast that it does not miss the food. In fact you look forward to it because of the many spiritual, mental and physical benefits that arise from it.

Appendix A Biblical Accounts of Fasting

* Moses fasted for forty days and forty nights while he was on the mountain with God. (Exodus 34:28)

* King Jehosaphat proclaimed a fast throughout Judah for victory over the Moabites and Ammonites who were attacking them (2 Chronicles 20:3).

* The prophet Isaiah chastised the Israelites for their unrighteous methods in their fasting. He clarified the reasons for fasting and listed the benefits that would result. “Is not this the fast that I choose: to loose the bonds of wickedness, to undo the straps of the yoke, to let the oppressed go free…. Is it not to share your bread with the hungry and bring the homeless poor into your house; when you see the naked, to cover him, and not to hide yourself from your own flesh? Then shall your light break forth like the dawn, and your healing shall spring up speedily; your righteousness shall go before you; the glory of the Lord shall be your guard” (Isaiah 58:3-13).

* The prophet Joel called for a fast to avert the judgement of God.

* The people of Nineveh in response to Jonah’s prophecy, fasted to avert the judgement of God (Jonah 3:7).

* Jesus also warned against fasting to gain favor from men. He warned his followers that they should fast in private, not letting others know they were fasting (Matthew 6:16–18).

* Jesus fasted for forty days and forty nights while in the desert, prior to the three temptations (Matthew 4:2, Luke 4:2).

* The prophetess Anna, who proclaimed the birth of Jesus in the Temple, fasted regularly (Luke 2:37).

Appendix B Quotes from the Saints on Fasting

 St Symeon the New Theologian:

Let each one of us keep in mind the benefit of fasting… For this healer of our souls is effective, in the case of one to quiet the fevers and impulses of the flesh, in another to assuage bad temper, in yet another to drive away sleep, in another to stir up zeal, and in yet another to restore purity of mind and to set him free from evil thoughts. In one it will control his unbridled tongue and restrain it by the fear of God and prevent it from uttering idle and corrupt words. In another it will invisibly guard his eyes and fix them on high instead of allowing them to roam hither and thither, and thus cause him to look on himself and teach him to be mindful of his own faults and shortcomings.

Fasting gradually disperses and drives away spiritual darkness and the veil of sin that lies on the soul, just as the sun dispels the mist. Fasting enables us spiritually to see that spiritual air in which Christ, the Sun who knows no setting, does not rise, but shines without ceasing.

Fasting, aided by vigil, penetrates and softens the hardness of heart. where once the vapors of drunkenness were causes of fountains of compunction to spring forth. I beseech you, brethren, let each of us strive that this may happen in us! Once this happens we shall readily, with God’s help, cleave through the whole sea of passions and pass through the waves of the temptations inflicted by the cruel tyrant, and so come to anchor in the port of impassibility.

Saint Nikolai of Zicha

Gluttony makes a man gloomy and fearful, but fasting makes him joyful and courageous. And, as gluttony calls forth greater and greater gluttony, so fasting stimulates greater and greater endurance. When a man realizes the grace that comes through fasting, he desires to fast more and more. And the graces that come through fasting are countless….

St. Nikolai Velimirovich

Bodily purity is primarily attained through fasting, and through bodily purity comes spiritual purity. Abstinence from food, according to the words of that son of grace, St. Ephraim the Syrian, means: ‘Not to desire or demand much food, either sweet or costly; to eat nothing outside the stated times; not to give one’s self over to gratification of the appetite; not to stir up hunger in oneself by looking at good food; and not to desire one or another sort of food.’

Abba Daniel of Sketis:

In proportion as the body grows fat, so does the soul wither away.

St. Dorotheos of Gaza

Everyone who wants to purify himself of the sins of the whole year during these days must first of all restrain himself from the pleasure of eating. For the pleasure of eating, as the Fathers say, caused all man’s evil. Likewise he must take care not to break the fast without great necessity or to look for pleasurable things to eat, or weigh himself down by eating and drinking until he is full.


The Holy Fathers have taught, as if with one voice, that the stomach is the gateway to the passions. Watchfulness in this area is, therefore, absolutely essential to spiritual progress.

Saint Seraphim of Sarov

The holy fasters did not approach strict fasting suddenly, but little by little they became capable of being satisfied by the most meagre food. Despite all this they did not know weakness, but were always hale and ready for action. Among them sickness was rare, and their life was extraordinarily lengthy.


To the extent that the flesh of the faster becomes thin and light, spiritual life arrives at perfection and reveals itself through wondrous manifestations, and the spirit performs its actions as if in a bodiless body. External feelings are shut off, and the mind that renounces the earth is raised up to heaven and is wholly immersed in the contemplation of the spiritual world.

St. Shenuda, Coptic Orthodox Church:

Consistent fasting regulated the lives of the Fathers. A stable lifestyle, to which they become accustomed regulated their lives. As for the pitied laymen, they sway from one extreme to another when fasting. They deprive themselves of food only to break their fast to partake of anything they desire. They abstain for awhile to allow themselves what they want for another period, then go back to indulgence, thus they sway between abstention and indulgence. They build, then destroy, and then build again, only to demolish again without recovery. True fasting is to train oneself in self-control, to follow for the rest of your life. Self-control becomes a blessing for his life, not only during the time of fasting when we change the time and the food we eat, but also during the normal days.

Evagrios the Solitary, a student of Saint John Chrysostom and desert monk who lived in the remote Egyptian desert, describes why fasting is so prominent in Christian life:

Fast before the Lord according to your strength, for to do this will purge your iniquities and sins; it exalts the soul, sanctifies the mind, drives away the demons, and prepares you for God’s presence… To abstain from food, then, should be a matter of our own choice and an ascetic labor.

Metropolitan Kallistos Ware writes,

Ultimately, to fast is to love, to see clearly, to restore the original beauty of the world. To fast is to move away from what I want to what the world needs. It is to liberate creation from control and compulsion. Fasting is to value everything for itself and not 12 simply for ourselves. It is to be filled with a sense of goodness, of Godliness. It is to see all things in God and God in all things.

Anestis Keselopoulos

The central position that fasting holds in the tradition of the Orthodox Church is neither coincidental nor unrelated to the ecological crisis but has unmistakable prophetic significance. Fasting is not some outward conventional act but the voluntary privation of food that heightens man’s awareness of his dependency on the outside world. This awareness has decisive importance for ethics. By fasting, man obediently accepts the divine commandment so that he can grow into the likeness of God. In so doing, he recognizes his created nature. In other words, he acknowledges that his ‘very being is on loan.’

Appendix C Glossary of Terms


The vital or functioning tissues of the fasting organism are nourished off the food reserves stored in the body. These reserves are stored as rather complex substances, such as sugar (glycogen), fat, protein, etc., and are no more fitted for entrance into the bloodstream and use by the cells than are the fats, proteins and carbohydrates of another animal, or another food. Before they can be taken up by the circulation and assimilated by the cells, they must first be digested. Autolysis (a-tol-i-sis) is derived from the Greek and means, literally, self-loosing. It is used in physiology to designate the process of digestion or disintegration of tissue by ferments (enzymes) generated in the cells themselves. It is a process of self-digestion–intra-cellular digestion.

 Fasting and tumors

Abnormal growths possess a lower grade of vitality than normal growths, hence are easier to destroy. I think it may be equally true that they do not command the support of the organism as do normal growths, as they are lacking in nerve and blood supply. This lack of support makes them the ready victims of the autolytic processes of the body. It is generally held by men with wide experience with the fast that abnormal tissues are broken down and eliminated more rapidly than normal tissue during periods of abstinence. Physiologists have studied the process of autolysis, although they have suggested no practical use that may be made of it save that of employing it to reduce weight. It now remains for physiologists to learn that by means of rigidly controlled autolysis, the body is able to digest tumors and utilize the proteins and other food elements contained in them to nourish its vital tissues. Why have they not investigated this vitally important subject? The facts have been before the world for more than a hundred years.

 More than a hundred years ago Sylvester Graham wrote: “It is a general law of the vital economy, that when, by any means, the general function of decomposition exceeds that of composition or nutrition, the decomposing absorbents always first lay hold of and remove those substances which are of least use to the economy; and hence, all morbid accumulations, such as wens, tumors, abscesses, etc., are rapidly diminished and often wholly removed under severe and protracted abstinence or fasting” (The Science of Life, pp. 194-195).

The process of autolysis may be put to great practical use and may be made to serve in getting rid of tumors and other growths. To fully understand this, it is necessary for the reader to know that tumors are made up of flesh and blood and bone. There are many names for the different kinds of tumors, but the names all indicate the kind of tissue of which the tumor is composed. For example, an osteoma is made up of bone tissue; a myoma is composed of muscular tissue; a neuroma is constituted of nerve tissue; a lipoma consists of fatty tissue; a fibroma is composed of fibrous tissues; an epithelioma is composed of epithelial tissue, etc. Growths of this nature are known, technically, as neoplasms (new growth) to distinguish them from mere swellings or enlargements. A large lump in the breast may be nothing more than an enlarged lymphatic gland, or an enlarged mammary gland. Such an enlarged gland may be very painful, but it is no neoplasm.

Tumors being composed of tissues, the same kinds of tissues as the other structures of the body, are susceptible of autolytic disintegration, the same as normal tissue, and do, as a matter of experience, undergo dissolution and absorption under a variety of circumstances, but especially during a fast. The reader who can understand how fasting reduces the amount of fat on the body and how it reduces the size of the muscles, can also understand how it will reduce the size of a tumor, or cause it to disappear altogether. He needs, then, only to realize that the process of disintegrating (autolyzing) the tumor takes place much more rapidly than it does in the normal tissues.

 Additional Information

The single most scientifically proven advantages to traditional fasting involve improved health, rejuvenation and extended life expectancy. Part of this phenomenon is caused by a number of the benefits mentioned above. These include a slower metabolic rate, more efficient protein production, an improved immune system, and the increased production of hormones all combine and contribute to these long-term benefits of fasting. In addition to the Human Growth Hormone that is released more frequently during a fast, an anti-aging hormone is also produced . The medical conclusion is “the only reliable way to extend the lifespan of a human, (or any mammal) is undernutrition without malnutrition.”

A study was performed on earthworms that demonstrated the benefits of an extension of life due to fasting. The initial experiment was performed in the 1930s by isolating one worm and putting it on a cycle of fasting and feeding. The isolated worm outlasted its relatives by an amazing nineteen generations, while still maintaining its youthful physiological traits. The worm was able to survive on its own tissue for months. Once the size of the worm began to decrease, the scientists would resume feeding it at which point it showed great vigor and renewed energy. “The life-span extension of these worms was the equivalent of keeping a man alive for 600 to 700 years.”