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Three Helpful Principles of Fasting: A Letter to a New Convert

Simplicity, Satiety, and a Litmus Question

Dear _________, 

You ask about guidelines for fasting and whether all the rules you have read about amount to legalism. I will try to answer you as best as I can.

One quickly finds in Orthodoxy today that, when it comes to the more minor or secondary rules for practicing any given fast, there are a lot of different opinions as to what is proper practice. This can be quite confusing for the zealous convert. As in all things Orthodox, one must endeavor to walk the Royal Way of moderation, neither rigidly adhering to the law—and judging those who do not—nor modifying it to suit one's taste (all in the name of "oikonomia"). But this is not all that easy, as I have intimated to you in our past correspondence, because the "rules" for fasting seem to be different depending on which authority one consults. In other words, the fundamental basics are easy to discern and to follow—abstain from all animal products (with the exception of shell fish), olive oil, and wine (unless permitted on a specific day), etc.; but then comes the problem of the number of meals per day (one, two, or three?), the preparedness of it (cooked? "tasty"?, etc.), and whether canola oil or margarine should be disqualified on non-oil days, whether beer is considered a form of "wine," etc. Fretting over these details can really become a trap. Do not fall into it. As you know, what Fr. _____ advises is what is right for you, for he knows your soul and your weaknesses. It is best when the sanctifying practices of the Church are applied by an experienced guide, i.e., your Father-Confessor.

In this vein, one finds the following in The Path to Salvation. St. Theophan the Recluse is discussing the pitfalls that one can fall into when trying to live a spiritual life: "The beginner should agree that these [pitfalls] are very cogent reasons for having a guide, and he should therefore choose one and entrust himself to him. He will be safe under his guidance as under a protective veil or in a fortress, for the guide will answer for him before God and man for his mistakes. But what is truly wonderful is that anyone who sincerely seeks will be given a true guide. And that guide, no matter who he might be, will always give exact and true counsel once the guided one entrusts himself with all his soul and faith. For the Lord Himself watches over one who is so trustful. Pray, and the Lord will show you a guide. Entrust yourself to this guide, and the Lord will teach him how to lead you" (p. 214).

Having said this, I will briefly tell you my opinion, gleaned from my own experience, discussions with various clergy, and reading the Holy Fathers, of one aspect of how to keep the spirit of the Fast. I also suggest you read the superb article on this very subject by Bishop Kallistos in The Lenten Triodion. If you do not already own this book, get a copy of it and read his article.

What is one of the things Jesus said about the Law? It can be summed up in two phrases: Love God, and love your neighbor as yourself. In this vein, I would like to suggest that all of the ostensibly confusing rules about fasting, above and beyond the foundational "no animal products, olive oil, or wine" rule—as helpful, though as hard to obtain consensus on today, as they are—can be summed up in two phrases: Eat simply, and stop before satiety. What do I mean by this? First, eating simply means that one's food preparation should not be of the normal, non-fasting type: sumptuous, fattened, and designed to excite the palate. This only reinforces one's love for food. This does not mean that the preparation should result in food that is repugnant. Rather, it means that it should not inflame one's desire for more, nor incite one (e.g., overly spicy or rich-tasting recipes). It should be such that it is simple, meager, and life-sustaining. It is still permissible for the food to be interesting and pleasant to eat (after all, it is not a sin to enjoy food in moderation). 

In this way one avoids being pharisaical. What would be an example of Pharisaism in the Fast? Aside from judging one's brother because they do not keep the fast "like I do," it would entail keeping the letter of the fasting rules but overlooking the weightier matters of simplicity and stopping short of satiety. Thus, one eats a delightful and extensive plate of Chinese food and then tops it off with a piece of tofu chocolate cheesecake (we have such things in our area!)—all "Lenten" of course. One could go through all of Lent "keeping the law" in this manner, never feeling hunger, never denying the palate's desires (are there not so many vegan options these days, given the chameleon-like tofu?), even gaining weight! This is sad but true. Avoid such a pitfall. If you eat simply then all of the debate about whether margarine is OK, or beer on a non-wine day, or whatever, are put in perspective. Such rules can be helpful guides, but they should not become your focus. One will find a difference of opinion on these "gray areas" wherever one turns (this is why you should just do what Fr. _____ says concerning such things). Some say margarine is "WRONG," others say it is not; some say beer should not be allowed on (non-wine & oil) fasting days etc., ad nauseum. And even if you were to get all the gray areas "right," you could still prepare a cornucopia of very tasty food and violate the spirit of the Fast. "Sumptuous eating deprives us of piety" (St. Nicodemos the Hagiorite).

This leads to the matter of something to which I have already alluded: quantity. This is relative for each person. One man's buffet is another man's morsel. There are, however, general rules discernible from the Holy Fathers. Especially during a Fast or on the Wednesday and Friday regular fasts, one should simply eat to sustain life (which is a far smaller quantity of food than we think—one of the reasons for the three days of total abstinence to start off Lent: shrinking the stomach), which means stopping short of satiety at each meal. For you this may mean three small meals a day. For others it may mean one. It depends upon one's physical makeup, job, etc. It is a matter for one's Father-Confessor, as is all of this.

Now, as to how satiety is defined. If you are like me, it can be difficult to determine when you are nearing the point of satiety. This is in part due to the problem of nailing down an clear and Orthodox definition of this term. I kept running across the word in Orthodox writings, but it was never adequately defined until I discovered the book I am about to mention. But let me first give you the definition from Webster's New World Dictionary: "The state of being satiated; surfeit." The word "satiate" is defined as "having had enough or more than enough, sated;... 1. [Now Rare] to satisfy to the full; gratify completely 2. to provide with more than enough, so as to weary or disgust; glut; surfeit.... in current use satiate almost always implies...a being filled or stuffed so full that all pleasure or desire is lost;...surfeit implies a being filled or supplied to nauseating or disgusting excess...." 

These definitions are useful, but they need some refinement in order fully to grasp the Orthodox use of the term. The little-known gem Elder Basil of Poiana Marului: His Life and Writings (St. John of Kronstadt Press, 1996) has been very helpful to me in this matter. This is a very important book, and it ultimately clarified things for me. Elder Basil was the spiritual father of St. Paisii Velichkovsky, one of the Saints behind the Philokalia. Elder Basil's writings mainly consist of introductions to themes and books in the Philokalia. The latter is, if you do not already know, mainly for spiritually advanced people. (There are, however, some sections of the Philokalia that can be read by beginners, like the Ascetic Discourse by St. Mark the Ascetic, among other things.) The Elder writes introductions and overviews that help the average or beginning struggler (particularly monks) to grasp the rudiments of the ascetic life. Here are some excerpts concerning fasting, and especially the term "satiety." Each one gives a slightly different translation of the same passage from St. Gregory of Sinai. I thought that all three variations were helpful to the task of discerning how much we should eat. Keep in mind that these passages are speaking of the continual life of a monk outside of Lent. However, the principles therein are very instructive for us:

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Adopting such a rule concerning food, do not put all of your effort and hope in fasting alone. Instead, while fasting according to your measure and strength, concentrate on noetic work. If you have the strength to be satisfied with bread and water, then that is good. It is said that no other foods strengthen the body as bread and water do. However, do not think that by doing this, you are practicing some virtue in fasting, expecting to acquire self-restraint by fasting. If you are weak, let your fasting be with discernment, says St. Dorotheos.

St. Gregory of Sinai gives these directions:

You who strive after salvation should be satisfied with one litra [3/4 lb.] of bread and three or four cups of water or wine a day, and a little of any other victuals which may be to hand. You must not let yourself eat to satiety. By thus eating all kinds of food you can both avoid boastfulness and avoid disdaining God's creations which are most excellent; and you thank God for everything. Such is the reasoning of the wise! If you eat all the kinds of food at hand and drink a little wine, but doubt your salvation because of this, this is lack of faith and a disability of thought....

The measure of partaking of food that is free from sin and pleasing to God has three degrees: abstinence, adequacy and satiety. To abstain means to remain a little hungry after eating; to eat adequately means neither to feel hungry nor weighed down. But eating beyond satiety is the door to gluttony through which lust comes in. But you, firm in this knowledge, choose what is best for you, according to your powers, without violating the established rule: for the perfect, according to the apostle, whether they be satisfied or in hunger, are mighty in all ways" [Philippians 4:12-13] (p. 53)

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Whoever wants to be instructed in this first let him understand and do what St. Maximos said, "Provide for the body according to its strength and devote all your struggle to the mind." And again, "Physical virtues are pleasing [to God] if they are done with humility; without this our labor is in vain." And likewise, "Do not devote all of your effort to the flesh, but set it a limit of abstinence corresponding to its strength and turn your whole mind towards internal matters; for bodily training is of little benefit."

St. Hesychios says of this:

He that does not know how to travel the spiritual path does not take concern or correct his passionate thoughts, but devotes all of his exercise and care to the flesh. Such a person is either a glutton and dissipated, or gets depressed, loses his temper, holds grudges and thus darkens his mind, or through excessive abstinence he misses the mark and disturbs his mind.

Again, St. Diadochos says:

The same way as the body, being weighed down by abundance of food, makes the mind somehow cowardly and ill-tempered, so also it can weaken the mind through excessive abstinence and bring it to a state that is somewhat feeble and disinclined to behold worthy ideas. In opposition to bodily movements, one should make proper use of food, so that when the body is healthy it be wearied as much as is needful. But when it is ailing, let it be strengthened moderately. For the ascetic should not exhaust his body but provide for it so as to be able to practice his asceticism.

Yet again, St. John Climacus says, "I have seen this enemy put at ease and imparting vigilance to the mind" and so on. For we ought to have a body that is healthy but not uncontrolled, because noetic work requires physical strength. Therefore one must mightily flee from both excessive fasting and from laxity.

We recommend the rule laid down by St. Gregory of Sinai, who said of this:

For those who are still forcing themselves, a pound of bread is sufficient, and three or four cups of water or wine, according to the day, is enough for one who wants to find God. As for the sweets that may be at hand, take a little of each but not to satiety, so as to escape conceit and not disdain the good creations of God, giving thanks to Him for everything. Such is the reasoning of the wise. For those who are weak in the faith, abstinence in food is very beneficial, for it is them that the apostle commands to eat greens [Romans 14:2], because they do not believe that they are protected by God.

There are three degrees of eating: abstinence, adequacy and satiety. Abstinence is when one is hungry after eating. Adequacy is when one is neither hungry nor weighed down. Satiety is when one is weighed down a little. To eat beyond satiety is the door to gluttony through which lust enters in. And so, examine all this and chose what is suited for your strength, without violating the rules. It is for the perfect, and this is according to the apostle, to go hungry and to be filled and in all things to be strong [Philippians 4:12-13] (pp. 77-79).

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While we have seen many of the saints performing fastings and labors that surpass human nature, on our part we must learn from many fathers with divine vision not to want to undertake those disciplines that surpass human nature, because we have not received that sort of power and heavenly fire. It is better for us to submit ourselves to the divine Gregory of Sinai and follow his rules which are good and measured, because he writes saying:

For those who are struggling one pound of bread is enough and for the one who wants to find God let him also eat a bit of all the foods which happen to be at hand, just enough not to be sated, in order to avoid conceit and also so as not to despise the good creation of God, but to be thankful for everything. This is the discernment of the wise. As for those who are weak in faith or in soul, it would be better to abstain from such foods. These are the ones the apostle commands to eat greens, since they do not believe that they are protected by God [Romans 14:2].

There are three levels of partaking of food: abstinence, adequacy and satiety. The first means to be still hungry after you have eaten (that is, to get up from the table still a little hungry). Adequacy means to be neither hungry nor to be weighed down with food, while satiety is to be somewhat weighed down with the food. To eat beyond satiety (this means to eat after you have left the table or the meal) is the gate of the stomach through which lust enters in. Therefore, discerning these things, choose for yourself what is best suited to your strength without going beyond the limits of our rule. Because it is possible only for the perfect, according to what the apostle says, to be both hungry and filled and yet to be powerful in all things [Philippians 4:12-13].

The blessed Nil Sorsky says the same. He says that the measure for beginners is to leave the table slightly hungry, and if someone eats enough to be satisfied this is not a sin. However, if a person becomes somewhat weighed down with the food, he should reproach himself and then he will achieve victory (pp. 117-119).

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There is also an instructive passage in A Handbook of Spiritual Counsel, by St. Nicodemos (Chapter 6):

The Three Degrees of Eating

According to St. Gregory the Sinaite there are three degrees in eating: temperance, sufficiency, and satiety. Temperance is when someone wants to eat some more food but abstains, rising from the table still somewhat hungry. Sufficiency is when someone eats what is needed and sufficient for normal nourishment. Satiety is when someone eats more than enough and is more than satisfied. Now if you cannot keep the first two degrees and you proceed to the third, then, at least, do not become a glutton, remembering the words of the Lord: "Woe to you that are full now, for you shall hunger" (Lk 6:25). Remember also that rich man who ate in this present life sumptuously every day, but who was deprived of the desired bosom of Abraham in the next life, simply because of this sumptuous eating. Remember how he longed to refresh his tongue with a drop of water. St. Basil not only did not forgive the young people who ate to satiety but also those who ate until satisfied; he preferred that all eat temperately. He said, "Nothing subdues and controls the body as does the practice of temperance. It is this temperance that serves as a control to those youthful passions and desires."' St. Gregory the Theologian has also noted in his poetry: "No satiety has brought forth prudent behavior; for it is in the nature of fire to consume matter. And a filled stomach expels refined thoughts; it is the tendency of opposites to oppose each other. "Job, too, assuming that one could fall into sin through eating, offered sacrifice to God for his sons who were feasting among themselves. "And when the days of the feast had run their course, Job would send and sanctify them, and he would rise early in the morning and offer burnt offerings according to the number of them all; for Job said: 'It may be that my sons have sinned, and cursed God in their hearts'" (Jb 1:5-8). In interpreting this passage Olympiodoros wrote: "We learn from this that we ought to avoid such feasts which can bring on sinfulness. We must also purify ourselves after they have been concluded, even if these are conducted for the sake of concord and brotherly love as in the case of the sons of Job." Surely then, if the sons of Job were not at a feast but in prayer or some other spiritual activity, the devil would not have dared to destroy the house and them, as Origen interpreted the passage: "The devil was looking for an opportunity to destroy them. Had he found them reading, he would not have touched the house, having no reason to put them to death. Had he found them in prayer, he would not have had any power to do anything against them. But when he found an opportune time, he was powerful. What was the opportune time? It was the time of feasting and drinking." Do you see then, dear reader, how many evils are brought forth by luxurious foods and feasting in general?

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Here is a short quote from The Little Russian Philokalia, Vol. II, from the Counsels of Elder Nazarius of Valaam:

And so, partake of the dishes which are offered in silence and with prayer, and do everything as written above. At the same time guard yourself carefully also in this: Satisfy your body with food in such a way that you do not feel full or heavy, but have still a little hunger and thirst. Nourish rather your soul with the God-inspired words and lives of the Holy Fathers which are read during trapeza... .

Having reflected thus, at least say to yourself from your whole soul and with heartfelt sorrow: Eat, unworthy one, enough so that you will not die. Dry up your body; confine your insatiable desires; grieve and belittle yourself. Will not the most merciful Lord look down upon this grief and contrition of my heart which are justly deserved? Even though my contrition itself is imperfect and insufficient, will not God Who is endless in mercy still have mercy on me and forgive the great evils that I have done?

Constantly reflecting thus and reproaching yourself, decide for yourself how much you should eat and drink every day to satisfy the needs of nature. Avoid as much as possible not merely overeating, but even eating just enough to be full. Keep in mind what was said above, that one should eat and drink only to the point where one is still a little hungry and thirsty.

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And finally, this helpful passage from The Prologue from Ochrid, by St. Nikolai Velimirovich (Volume 4, p 338):

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 oneself 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.'

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If you adhere to these two principles, checking yourself with a third (below), everything falls into place. No longer does one have to fret over the various secondary rules. If you keep these two principles you will fast better than most of those in the Church who even fast at all. For most of those who do "keep the Fast," do so in a way that evinces adherence merely to the most basic rules and not to the grace-bestowing spirit of the Fast. Thus, their efforts are in vain.

I mentioned a third principle. This is really more of a litmus question you can ask to help determine whether you are  walking on the Royal Way. It is, "Do I regularly feel 'light' and at peace in body, frequently a little hungry (i.e., a "humility in flesh," or a measure of bodily weakness)—but not overly distracted or continually troubled by hunger—and disposed towards prayer?" (Another similar question: "Is the food I am about to eat something I need for strength of body—that my soul might not be overly burdened with bodily needs—or am I eating out of mere pleasure or boredom?") On this matter St. Dorotheos of Gaza writes in his Discourses and Sayings:

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.

There are two kinds of gluttony. There is the kind which concerns taste: a man does not want to eat a lot but he wants it to be appetizing. It follows that such a person eats the food that pleases him and is defeated by the pleasure of it. He keeps the food in his mouth, rolling it round and round, and has not the heart to swallow it because he enjoys the taste. This is called fastidiousness (lairmagia). Another man is concerned about satisfying himself. He doesn't ask for fancy food nor does he care especially about whether the taste is nice or not, he only wants to eat and fill his stomach. This is gluttony. I will tell you how it gets this name: margainein means to rage furiously, to be mad; according to the profane, margos is the name given to the man who rages furiously or is mad. When this disease or mania for packing his belly full of food comes upon a man, therefore, it is called gastromargia, the madness of the stomach, whereas lairmargia is the madness of the palate. These must be guarded against and abandoned seriously by the man who desires to be cleansed of his sins. They accord not with the needs of the body, but with its vicious inclinations, and if they are tolerated, they lead a man into sin. As is the case with legitimate marital union and fornication, the practice is the same but the object is different. In the one case, there is copulation in order to raise a family, in the other, to satisfy a desire for pleasure. The same is true with feeding: in one case it is a question of the body's needs and in the other of eating for pleasure. The intention is what makes it a sin. A man eats to satisfy a need when he lays down how much he will take each day and, if what he has determined on overloads him, takes a little less, or if he is not overloaded and his body is weakened, adds a little. And so he estimates exactly his need, and he bases his conclusion not on pleasure but on preserving the strength of his body. And what he takes he receives with prayer, deeming himself unworthy of that comfort and he is not on the look out to see if others, as is likely, because of special need or necessity are given special attention, lest he himself hankers for that comfort or think it a trivial thing for the soul to be at rest.

If you can answer "yes" to this litmus question, you are on the right path. If "no"—if instead, you feel like most people feel much of the time: fuzzy-minded (especially in prayer), "heavy," not disposed towards moderation in food intake, lustful, irritable, etc.—, then you need to course-correct. It is as simple as that. Of course, this is not a question to ask yourself every hour. It is, rather, something to take stock of relatively frequently. It is helpful to keep a journal, especially if food is something that is a passion for you. 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. As St. Gregory Palamas once wrote, "[E]ven satiety with cheap foods prevents the cathartic mourning and the godly sorrow in the soul and the compunction which shapes firm repentance for salvation; for without a broken heart it is not possible to enter truly into repentance" (St. Gregory Palamas as a Hagiorite, by Metropolitan Hierotheos of Nafpaktos).

I hope this helps. Just remember the "two S's": simplicity and satiety. These "buzzwords," recalled whenever an opportunity to eat presents itself, will keep you in remembrance of the spirit of the Fast and guide you through the gray areas. It will help you to know whether you are keeping the Royal Way or living as a Pharisee in disguise. Your aim is to try at all times, even out of fasting periods, to divorce yourself from an attachment to, and love of, food. As St. Nicodemos once wrote, "the root of virtually all of life's faults lies in one's inordinate preoccupation with food" (A Handbook).

In closing I should add that proper fasting will likely take years of practice. I myself have a long way to go in this area. We will fall numerous times from the ideal that I have attempted to sketch out here. The important thing is not to focus on the success or failure of your efforts. This is a tactic of the devil. What God wants from us is the struggle. He wants us to "prepare a way for the Lord" in our hearts. And then what we sow, He waters. The increase of Grace that accompanies such plowing up of our heart's fallow ground (using the spade of fasting) is a gift from God and comes when He chooses to send it. This gift should not be our focus, lest we even rise up in anger that God has not given what is "owed to us." All we need do is be faithful in our struggle, endeavor to keep to the path as much as possible, and God will honor it all richly. He will meet us where we are. Do the best you can, confess weekly, and ask yourself often whether you are on the path. In this way your fasting struggles will bear much fruit.

Sincerely in Christ,

______________

P.S. I have appended some helpful quotes from the very important work, The Arena: An Offering to Contemporary Monasticism, by St. Ignaty Brianchaninov (Jordanville, NY: Holy Trinity Monastery, 1991), pp. 131-135, 262. These quotes are written for novice monks living in the mid-late 19th century. One can easily apply the principles in this book to much of modern living as a lay person:

In order to remain in vigilance, it is necessary to guard the freshness and brightness of the mind with all care. The mind becomes darkened from imprudent use of food, drink and sleep, from much talking, from distraction and from worldly cares. Attend to yourselves, said the Lord, be on your guard and take care that your hearts are never weighed down, dulled and depressed by self-indulgence, overeating and drinking, or worldly cares and pleasures, lest that day (the day of Christ's dread judgment, the last day of the world) catch you unawares. For it will spring like a trap upon all who are living on the face of the earth. So watch and pray at all times for the strength to escape or survive all that is going to happen, and to stand before the Son of Man [Luke 21:34-36].... (pp. 131-132)

Having guarded ourselves against distractions and worries, let us turn our attention to our body on which mental vigilance is completely dependent. Human bodies differ widely from one another in strength and health. Some by their strength are like copper and iron; others are frail like grass. For this reason everyone should rule his body with great prudence, after exploring his physical powers. For a strong and healthy body, special fasts and vigils are suitable; they make it lighter, and give the mind a special wakefulness. A weak body should be strengthened by food and sleep according to one's physical needs, but on no account to satiety. Satiety is extremely harmful even for a weak body; it weakens it, and makes it susceptible to disease. Wise temperance of the stomach is a door to all the virtues. Restrain the stomach, and you will enter Paradise. But if you please and pamper your stomach, you will hurl yourself over the precipice of bodily impurity, into the fire of wrath and fury, you will coarsen and darken your mind, and in this way you will ruin your powers of attention and self-control, your sobriety and vigilance. (pp. 133-134)

Just as we must beware of overeating, so too we must beware of excessive temperance or abstinence. Excessive temperance weakens the body, destroys wakefulness, coolness and freshness which are indispensable for vigilance, and which fade and weaken when the physical powers succumb and fail. Said Saint Isaac the Syrian: 'If you force a weak body to labour beyond its powers, you subject your soul to double darkness, and lead it into confusion (and not relief). But if you give a strong body rest and ease and idleness, all the passions dwelling in the soul are intensified. Then, even if the soul has a great desire for good, even the very thought of the good that is desired will be taken from you ... . Measure and time limits in discipline illumine the mind and banish confusion. When the mind is upset by a disorderly or imprudent life, darkness clouds the soul; and with darkness comes disorder and confusion. Peace comes from order; light is born from peace of soul. And from peace, joy fills the mind.' [Mystic Treatises, Chs. 46 and 45]

Constant and unfailing vigilance is secured by prudent temperance. Constant vigilance secures a faithful following of the Gospel teaching. The Gospel teaching is the only source of all true, Christian, God-pleasing virtues. (p. 135)

The use of food both in the refectory and in the cells should be regulated by prudence in regard to quantity. Novices should take food almost to fullness, but not to satiety. Fasting, which is so useful for a monk later, in the case of a novice should be moderate. If a novice does not eat outside the refectory, such a fast will be fully sufficient for him. The partaking of food in the refectory almost to fullness is necessary for a novice because he is obliged to do his obediences which are sometimes difficult, and so as not to weaken his bodily strength excessively. For the due weakening of the body, the quality and quantity of the monastic food in the refectory is sufficient. The passions diminish in novices not through violent fasting, but through the confession of sinful thoughts, through labours, and, through shunning free intercourse with others. (p. 262) 

For further reading see On the Spirit of Gluttony (Book V from the Institutes of St. John Cassian) and Fasting and Science: A Study of the Scientific Support and Patristic Foundation for Fasting in the Orthodox Church, by Dr. Constantine Cavarnos (Etna, CA: Center for Traditionalist Orthodox Studies, 1988).