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Fasting Reconsidered: St. John Chrysostom and Modern Science on Fasting


With the existence of different fasting regulations among some Orthodox churches, both Eastern and Oriental, it is needful that principles be set forth that contribute to the unification of this invaluable and ancient practice contemporarily. It is important, however, that when ancient practices meet contemporary culture, that the practice be assimilated and appropriated not with uncertain caution but with the graced confidence of the Holy Spirit of wisdom. This requires faithfulness to all that God has revealed not just through Scripture, Tradition, and the life of the Church, but also through the latest developments in the sciences, which should never be incongruent with the former. It is important that the Orthodox Church, while maintaining its loyalty to its Patristic heritage, continue to incorporate, digest, and appropriate the latest contributions of modern medicine and scientific research. For this reason, I will present a synthesis of the ancient and the contemporary by focusing on the writings of St. John Chrysostom and Dr. Randi Fredricks, a leading authority and researcher on fasting.

St. John Chrysostom proved to be a man heavily concerned with the practical implementation of church regulations. Within his writings it is easy to find him on par with the concerns of the church community at all levels, suggesting behavioral and ethical guidelines by which to embody the spirit of the law. In this light, it is useful to focus on his writings in particular to guide the discussion on fasting. This will be especially helpful in conversation with the latest findings in the sciences concerning fasting. Dr. Randi Fredricks, a world-renowned leading researcher and expert on the science of fasting, published an important book on this topic in 2013 entitled Fasting: An Exceptional Human Experience. Her findings, alongside others that will be mentioned, help elucidate the relationship between the healthcare field and fasting and the resulting interplay between societal outlooks on religious fasting.

The discussion of fasting is not only needful as an ecumenical tool but it needs serious (re)consideration so as not to be used contrary to its intended purposes, which is often the danger with a longstanding practice—the original intent becomes obfuscated. This obscuring holds no partiality; fasting is in a triple conundrum, with pressures from opposing ends, one of which takes root in society and two of which sprout from the faithful. First, medical professionals often denounce fasting because of a misrepresentation of fasting.[1] This is likely a cumulative effect resulting from monastic texts exalting what may appear to be self-mutilation, from the concern of health risks and detrimental outcomes, or from a lack of convincing scientific research. With this disapproval comes arguments against any benefits to fasting, and this runs the risk of deterring the faithful from this necessary practice as the acquisition of medical knowledge is often coupled with a sense of a greater ability for autonomous decision making.

Additionally, the dangers that are internal to the Church follow from improperly approaching the practice of fasting from one of two extremes. The first is in the case of an oxymoronic hyper-moderation, which can act counter to its purported aim by holding moderation as an absolute. This in turn can be mistaken for indifference or warranted laxity and is not far from slipping into the repudiation of a valuable practice. The second case is one of a pharisaic legalism that can either become harmful to the body or that simply adheres to prescribed motions of abstinence or dietary restriction without concern for anything but adherence to a self-concocted spiritual rite that finds rest only in self-righteousness.

The goal of this paper is to offer bases on which to alleviate these tensions, which should not gain the upper hand, as fasting is an inextricable part of the human experience. A clear picture is fashioned through the harmonious pigments of the latest medical research and the practice of fasting, and it is important that this harmony be recognized and shared as common knowledge and as a vital component of Church education. While sufficiency could rest in the high esteem and frequent observance of fasting among the early Church Fathers, it is a staple of our time to act in congruence with personally attained knowledge. For this reason, I believe that the support of science and medicine is an integral part of encouraging the faithful to be entrenched wholeheartedly in the practice of fasting. By this, I am not implying that fasting should be observed because of physiological advantages. This obsession with creating lists of benefits that can often be irrelevant is coined by Scot McKnight in his book on fasting as “benefit-itis,” whose comical ring helps relay its counter effectiveness.[2] Instead, as I will discuss below, St. John Chrysostom and the top medical researchers on fasting agree at least on the three following points: fasting facilitates autonomous control, fasting significantly enables and grants freedom and elation, and fasting encompasses fundamental dimensions of holistic human flourishing.

Fasting as Recovery of Control

To begin, much can be said concerning Chrysostom’s extensive writings on asceticism, but in order to narrow the scope of this paper, I will mention texts of his that make explicit reference to fasting. Known in his time as “the monk,”[3] Chrysostom focused much on making arguments for ascetic practices that were both relevant to the scope of one’s daily life and theologically sound. Regarding fasting, Chrysostom says in Homily XIII on Matthew 4, “Adam by the incontinence of his belly was cast out of paradise.”[4] He continues by explaining that one of the “medicines of our salvation” is given us by the example of the Lord Jesus Christ through fasting, which restores our will, resolve, and power over the sway of the devil.[5] This way, humans are no longer under the control of bodily temptations but have regained control through governing the appetite. In addition to promising control, hunger cultivates virtue in its opposition to evil and its concord with good. Thus, for Chrysostom, in order to regain the authority given humanity in paradise, evil must be resisted; in order for evil to be resisted, one must possess full control over one’s body; and in order to possess this control, one must bridle the stomach through fasting.

While Chrysostom’s bases remained theological and experiential, Teresa M. Shaw’s work The Burden of the Flesh: Fasting and Sexuality in Early Christianity provides evidence for the correlation the monk put forth. More specifically, she refers to a number of experiments, the most exhaustive and conclusive of which was conducted at the University of Minnesota. This research noted a significant and positive correlation between an increase in caloric intake and an increase in sexual desire.[6] Cited alongside these results are estimated calculations of the caloric sum of St. John Cassian’s suggested diet for monks, which amounted to approximately 930 calories daily.[7] While the suggestion based on this calculation certainly would not be to resort to methods of semi-starvation, it is the idea of having control over one’s body that is most fruitful in this discussion. It should also be noted that this is not an invitation to improperly denounce human sexuality or the sexual experience as impure or sinful. Instead, these experiments point to the link between lower food intake and the recovery of control over one’s body. In this specific instance, instead of being enslaved, one is more capable of being intentional with one’s sexuality, possessing the power and ability to positively utilize this God-given gift. To this exact point St. John links “the corpulence that comes of gluttony” and the ability to “repel the tempest of evil thoughts” admitting that the former, that is gluttony, is a great hindrance to this end.[8] As a result, this study provides implications for a proactive solution to any societies or communities that have succumbed to an unfortunate increase in sexual perversion, and it also supports the conclusions reached by the monk centuries ago concerning the efficacy of fasting.

Fasting as Freedom from Bodily Impediments

It was not only a restoration to paradise and the regaining of control over the body that interested St. John regarding fasting. This control has a number of corollaries—important ones that feed into each other and that facilitate other aspects of the Christian struggle. Chrysostom writes, “He that fasts is light, and winged, and prays with wakefulness.” He continues by explaining that this accompaniment of prayer to fasting gives “double wings,” able to lift a person away from the cares and attachments to this world.[9] Not only does this grant control, but it grants power over what might otherwise be considered distractions to spiritual progress. The combination of fasting and prayer are crucial for Chrysostom, and this is further supported by a biblical retrieval of fasting in the life of the Lord Jesus Christ.

The most obvious example is His forty-day wilderness fast following His baptism and prior to the official mark of the beginning of His earthly ministry. The monk makes a case for fasting in this regard, stating that since Christ fasted after His baptism, so too should Christians observe this practice throughout the duration of their lives after their baptisms. Yet this is not the only case to make for Christ’s institution of this practice for His followers. In the synoptics,[10] when He is asked why His disciples do not fast, He replies that they will fast when He, the Bridegroom, leaves. It is soon after the confession and commemoration of this departure that the Orthodox Church observes the Fast of the Apostles. Moreover, this event serves as an impetus for the many fasts the Church in Her history implemented after Christ’s institution of the practice. The very institution of fasting is an important component of its effectiveness. While this presentation does indeed focus much on the physiology and psychology of fasting, it does not follow that fasting is not a mystical experience. As Vladimir Lossky asserts, the mystical theology of the East holds that spiritual realities are not to be overshadowed by philosophical endeavors.[11] Without opening a larger topic on the mysticism of fasting, suffice it here to note that Chrysostom and other early Fathers interpreted this event in the synoptics as a command by God. This is supported by Christ proclaiming “When you fast” instead of “If you fast” in Matthew 6.[12] It naturally follows that adherence to and observance of Divine command could and would be accompanied by experiences of that which is beyond the physical.

Dr. Randi Fredricks’ research on fasting supports this conclusion. She cites dozens of studies that correlate fasting to mystical experiences. Scientifically, these experiences can be described by a number of labels, including Exceptional Human Experiences (EHE’s), Altered States of Consciousness (ASC’s), and some renditions of the theory of the phenomenon of flow, a theory familiar to the vocabulary of both religion and science, none of which are to be confused by accusations of hallucination.[13] The repeated studies since the mid 20th century, beginning with Abraham Moslow and extending to dozens of contemporary researchers, have confirmed this correlation. These “peak experiences,” as they are sometimes identified, enable self-actualization and self-realization.[14] Fredricks concludes that fasting provides means by which to facilitate self- transcendence through its obvious ability to promote detachment from and the loosening of worldly ties, beginning with a removal from the reliance on food.[15] This in turn can produce altered states of consciousness that are present not simply physiologically from a depletion of dietary sustenance but also from the realization of the insufficiency of bodily reliance in guaranteeing happiness, freedom, and feelings of purpose and fulfillment. This is in perfect harmony with Patristic notions of the positive effects of fasting and serves to eliminate what may sometimes be a hesitancy either to trust developments in the sciences or to trust its congruency with religion. More importantly, it supports the Patristic experience that the mysticism that often accompanies fasting is not accidental but instead, fasting is a valuable outlet into ethereal realities.

Fasting as Holistic Human Flourishing

Arguably the most dominant of St. John Chrysostom’s foci on this topic harbors on a spirit of fasting that encompasses the entirety of a person’s well being. More specifically, the crux of fasting for Chrysostom is to aid in a person’s struggle against sin, and if the manner of fasting promotes sin in one way or another, it is not sincere fasting and should be discontinued.[16] He explains that all things are permitted to be eaten, and so if we abstain from those things that are permitted and yet do those things which are not, we lose the spirit of fasting.[17] Instead, the monk emphasizes that fasting should initiate positive change—a reformation of conduct toward a more virtuous self.[18] We should become unhabituated to sin by becoming habituated in good works, especially since he comfortably places charity and almsgiving—that is, expressions of love towards the other—above the physical practice of fasting.[19] This calls to mind the same spirit of fasting found in the book of Isaiah: “Is not this the fast that I choose: to loose the bonds of injustice...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 them...?”[20] The main focus of fasting then should be a complete transformation of one’s interior disposition from sin toward virtue. Chrysostom explains that even those who are unable to fast physically are still able to observe fasting periods by diverting their bodies from overindulgence. Yet, it remains true that the physical methods of fasting instructed by the Church prove effective in meeting these transformative ends. This holistic transformative effect is precisely what Dr. Fredricks demonstrates throughout her work.

Dr. Fredricks provides a significant amount of research and data, some original and self- conducted and others from a comprehensive study of the available data published in the field, that provide astounding links between fasting and the promotion of physical and psychological health.[21] Among a number of other benefits, fasting promotes physical healing on a number of levels, has been found to lower symptoms of depression, exhibits similar brain wave patterns as those induced by the practice of meditation, can help reduce grief, enhances mental clarity and performance, may decrease the likelihood of developing Alzheimer’s disease, and can help physically and psychologically with eating disorders.[22] The point here, however, is not to shift the impetus for fasting from the spiritual to the physical, but to show that science agrees that fasting extends beyond simple dietary constraints. Moreover, it is difficult to categorize these physical benefits as separate from or in opposition to spiritual benefits. The intimacy of body and spirit and the perpetual and profound effect each has on the other cannot be denied or overstated. To this end, the fact that fasting promotes physical well being can be a signal for its spiritual efficacy and vice versa. Similarly, the holistic promotion of the physiology and psychology of fasting signals a certain wholeness spiritually. Surely these must be appropriated with caution, but it would be rather difficult to make a case that concordant attestations by a reliable and exemplary Patristic account and a leading contemporary scientific account regarding the physical, psychological, and spiritual wholeness experienced through fasting are mere coincidence.

The correspondences do not end there. Fredricks’ research provides strong claims as to how a fast is to be approached in order to ensure that its benefits are experienced maximally. The type of fasting that Fredricks puts above all others is water-only fasting, and while this does not necessarily exemplify the most common practice among Orthodox Christians today, there is an important pragmatic technique she highlights that forms a lucid distinction between healthy, beneficial, and proper fasting on the one hand, and unhealthy, harmful, and improper fasting on the other. To be exact, the technique focuses on the process before, during, and after periods of fasting. There exist certain withdrawal symptoms when beginning a fast, and for this reason, experts in the field recommend a preparatory diet before fasting.[23] This can include eating a whole foods diet or a vegan diet low in salt, oil, and sugar.[24] This of course would be in preparation for water-only fasting, but it points to the importance of gradually entering a fast. This is in contrast to the frequented overindulging that is practiced before beginning a prescribed fasting period but in consonance with the rites of some Orthodox churches that have installed a preparatory week before Lent.

Furthermore, the healthier the body prior to fasting, the fewer withdrawal symptoms experienced, such as headaches, dizziness, and fatigue, allowing one to focus more on the aforementioned transformative benefits instead of a fixation on the difficulty and specifics of dietary modifications. This gradual progression is also advised during fasts as well as when breaking fasts.[25] High caloric intake is not advisable after long periods of caloric abstinence. Alternating between abstinence and overindulging may be even less beneficial than not fasting at all, as studies have shown a drastic drop in mental and physical performance with such habits.[26] To this point, St. John Chrysostom admonishes those who in his time exhibited gluttony and overindulgence before and after fasts, effectively impeding or reversing the progress made while fasting.[27]


It has been my objective to address the three concerns mentioned at the outset of this paper, and the synthesis of the ancient and the contemporary has made this possible. First, regarding the disdain with which the medical field may look at fasting and the possible negative effects it could have on the trust and adherence of the faithful to this practice, it is clear that this is the result of poorly relaying what exactly constitutes the true spirit of fasting and how it is to be observed for the benefit of body and spirit. Pragmatically, it should be a concern of the Church to acquire and disperse this education fully, faithfully, and accurately. In this way, fasting will claim a more positive image inside and outside the Church and the healthcare field, allowing its benefits to be widespread. Second, regarding the problem of hyper-moderation that can cause lax adherence to fasting or that can easily fall into repudiation of the tradition, it is clear that in order to experience the full power of fasting, serious effort needs to be input. EHE’s, ASC’s, and other medically attested mystical experiences of fasting are only attained when a certain level of fasting enables one to detach from worldly ties by first detaching from overindulging the stomach. Moreover, hyper-moderation ignores the fact that fasting impacts each and every day of the year, since the periods before and after fasts are crucial and since the health of the body even during non-fasting periods influences the way in which the body reacts during fasting. This in turn determines the level of focus one will be able to dedicate to reaping the benefits of this practice. Third, regarding the nullification of fasting fostered by a pharisaic legalistic spirit, this practice ought to be viewed as a holistic experience in which the cultivation of virtue is of utmost importance. Fasting ought to create freedom from bodily and spiritual impediments, allowing its practitioners to focus not only on their personal well being but also and consequently on the flourishing of the other. Thus, the corporality of Orthodox fasting is in keeping with the saying, “One can be damned alone, but saved only with others.”[28] It is through this true spirit of fasting that humanity regains its God-given control, receives its untainted freedom, and accesses an essential portal to the love of God and neighbor.

[1] Fredricks, Randi. Fasting: An Exceptional Human Experience. Bloomington, IN: AuthorHouse, 2013, 212. [2] McKnight, Scot. Fasting. Nashville, TN: Thomas Nelson, 2009, 142-143. [3] Florovsky, Georges V. Patrology-Patristics. Vol. 7, Ch. 11. St. John Chrysostom. [4] Chrysostom, John. Chrysostom: Homilies on the Gospel of Saint Matthew. Ed. Philip Schaff. Peabody, MA: Hendrickson, 1994, 80. [5] Ibid., 81. [6] Shaw, Teresa M. The Burden of the Flesh: Fasting and Sexuality in Early Christianity. Minneapolis: Fortress, 1998, 125-127. The study contained thirty-two males who consumed 3,492 calories daily for twelve weeks followed by an average of 1,570 calories for the following twenty-four weeks. This semi-starvation was reported to decrease sexual feeling and expression, nocturnal fantasies and emissions, and a reduction in semen volume and change in morphology. [7] Ibid., 127. [8] Chrysostom, John. Chrysostom: On the Priesthood ; Ascetic Treatises ; Select Homilies and Letters ; Homilies on the Statues. Ed. Philip Schaff. Peabody, MA: Hendrickson, 1994, 357. [9] Chrysostom, Matthew, 356. [10] Matthew 5, Mark 2, Luke 5 [11] Lossky, Vladimir. The Mystical Theology of the Eastern Church. London: J. Clarke, 1957, 42. [12] Piper, John. A Hunger for God: Desiring God through Fasting and Prayer. Wheaton, IL: Crossway, 1997, 69, scriptural emphasis mine. [13] Fredricks, Exceptional, x, 108-119. [14] Ibid., 108-110. [15] Ibid. [16] Chrysostom, Ascetic Treatises, 406, 357, 359. [17] Ibid., 370. [18] Chrysostom, Ascetic Treatises, 450-451, 459, and Chrysostom, Matthew, 74. [19] Chrysostom, Ascetic Treatises, 388, 450-451. [20] Isaiah 58:6-7. Parts of the texts were left out not because they changed the meaning, but because they were superfluous and not as focused for the point at hand. [21] See Fredricks, Randi. An Exploratory Study of the Effects of Water Fasting for Depression. N.p.: n.p., 2011. [22] Fredricks, Exceptional, 47-63, 86-105, 280-303. [23] Fredricks, Exceptional,17. [24] Ibid., 17, 172. [25] Ibid., 32-36. [26] Ibid., 94-95. The study Fredricks refers to demonstrated that traffic incidents increased during the fasting month of Ramadan in predominantly Muslim countries where the fast is often observed with drastic fluctuations in diet before the recommended 48 hours of fasting is reached in which the state of the brain is no longer glucose-dependent. [27] Chrysostom, Ascetic Treatises, 438-439. [28] Baab, Lynne M. Fasting: Spiritual Freedom beyond Our Appetites. Downers Grove, IL: IVP, 2006, 60.


  • Baab, Lynne M. Fasting: Spiritual Freedom beyond Our Appetites. Downers Grove, IL: IVP, 2006.

  • Chrysostom, John. Chrysostom: Homilies on the Gospel of Saint Matthew. Ed. Philip Schaff. Peabody, MA: Hendrickson, 1994.

  • Chrysostom, John. Chrysostom: On the Priesthood ; Ascetic Treatises ; Select Homilies and Letters ; Homilies on the Statues. Ed. Philip Schaff. Peabody, MA: Hendrickson, 1994.

  • Florovsky, Georges V. Patrology-Patristics. Vol. 7, Ch. 11. St. John Chrysostom.

  • Fredricks, Randi. An Exploratory Study of the Effects of Water Fasting for Depression. N.p.: n.p., 2011.

  • Fredricks, Randi. Fasting: An Exceptional Human Experience. Bloomington, IN: AuthorHouse, 2013.

  • Grube, George W. What the Church Fathers Say About--. Minneapolis, MN: Light and Life Pub., 2005.

  • Holy Bible: NRSV, New Revised Standard Version. New York: Harper Bibles, 2007.

  • Lossky, Vladimir. The Mystical Theology of the Eastern Church. London: J. Clarke, 1957.

  • Main, Keith. Prayer and Fasting, a Study in the Devotional Life of the Early Church. New York: Carlton, 1971.

  • McKnight, Scot. Fasting. Nashville, TN: Thomas Nelson, 2009.

  • Piper, John. A Hunger for God: Desiring God through Fasting and Prayer. Wheaton, IL: Crossway, 1997.

  • Shaw, Teresa M. The Burden of the Flesh: Fasting and Sexuality in Early Christianity. Minneapolis: Fortress, 1998.

Dr. Stephen Meawad is an Assistant Professor of Theology in the Department of Theology and Philosophy at Caldwell University and a Lecturer at Pope Shenouda III Coptic Orthodox Theological Seminary. He holds a doctoral degree in Theology from Duquesne University, with a particular focus in Christian Ethics. His book, "Beyond Virtue Ethics: A Contemporary Ethic of Ancient Spiritual Struggle" is available for pre-order at Georgetown University Press (to be released in March 2023). This paper was presented by Dr. Meawad at "The Conference in Preparation for the Great and Holy Council of the Orthodox Church" on June 27, 2016. is a place for Christian men and women to collaborate for the sake of our common edification by sharing their written works. As we strive to uphold a standard of doctrinal and spiritual soundness in the articles shared, we note nonetheless that the thoughts expressed in each article remain the author’s own and do not necessarily reflect those of Doss Press.


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