DIGIUNO

FASTING. – From the ecclesiastical Latin ieiunus, “fasting” is one who is empty of food. The adjective-noun then came to mean the exercise of one who fasts, i.e., fasting itself.

Summary:

I. Concepts

II. Fasting in the Bible

III. Subject and time of fasting

IV. Essence of fasting

V. Excusing causes from fasting

VI. Moral obligation

VII. Current status of the law on fasting

VIII. Fasting in non-Christian religions

I. Concepts

The same fast is also strongly recommended for the one who is to be baptized and for the priest who baptizes him (canons 753 §1, 808, 858 §1).

Fasting that one freely imposes upon oneself, as an exercise of virtue, outside the prescriptions of the Church, and which one regulates in its modalities, is called by theologians moral fast. It consists in abstaining from food and drink according to a rational regimen. If the motives inspiring it are merely human, e.g., bodily health, good physical disposition for better study, etc., it is called philosophy. If the motives are supernatural, it is instead called Christian fast. This fast is inspired above all by mortification and penance as a preventive measure against sin or as a means of satisfaction for sins committed.

This same fast, inasmuch as the Church not only approves its end but has fixed its regimen in its various details, is properly called ecclesiastical fast.

Fasting, if ordered to an honest end, e.g., to curb the movements of the flesh, to render the mind more apt for contemplation (Dan. 10:3), to make satisfaction for sins, to obtain, together with prayer, spiritual and temporal benefits, is an act of virtue.

To be such, however, it must be practiced with discernment, respecting in the exercise of the virtue of temperance the two ends from which reason cannot abstract: preserving life and the strength necessary to fulfill one’s duty.

Fasting is properly an act of the virtue of abstinence, the subjective part of the virtue of temperance, because it concerns the use of food, in which it is proper to the virtue of abstinence to find the just mean. It can, however, be commanded also by other virtues: by charity, by religion, by penance, by chastity, etc.

Fasting is a useful good and therefore is not commanded for its own sake, but only in view of the end to which it is useful. The benefits that can ordinarily be obtained through the practice of fasting can also be reached by other means, and therefore by the law of nature it is not absolutely commanded for all, but only for those to whom it is necessary and inasmuch as it is necessary for them.

Since, however, it is generally very useful to all, the Church has determined in this matter the natural law and has established a time and manner of fasting to be observed commonly by all.

It is moreover consonant with reason to regulate food intake (abstinence). That the flesh should dominate the spirit is something that no one can desire or approve. Now gluttony is, after lust, the strongest of the passions of the senses and often itself provides lust with fuel and incentive. It is therefore fitting that a precept should, at given periods and recurrences, through its external observances, awaken in the soul the memory of what it has to fear from the body and offer it a practical and effective means of keeping the body subject to itself.

That the mortification of gluttony can constitute an act of religion and of worship appears so natural that it is found practiced in many religions, even non-Christian ones. Already in the books of the Old Testament, fasting and prayer together were reckoned among the most proper means to obtain graces from God.

II. FASTING IN THE BIBLE

The Jews were obliged to fast on the tenth day of the seventh month. During the captivity, the fasts of the 4th, 5th, and 10th months were instituted. Isaiah, however, noted that the Lord could not be placated by external fasting alone without true penance and the observance of the virtues of justice and charity.

In the New Testament, Jesus Christ fasted for forty days and forty nights before beginning His preaching of the Gospel; yet to His disciples, as long as they were with Him, He did not impose a precept of fasting, even to counteract the exaggerations of the Pharisees, who had multiplied fasting days to excess (Lk. 18:12). To His disciples themselves He announced that later they would fast (Mt. 9:14-15) and prescribed the manner of fasting, saying to avoid ostentation and hypocrisy (Mt. 6:16-18).

Sacred Scripture reports that the Apostles often fasted, especially in the election of ministers of God (Acts 13:2-3; 14:22). Paul expressly places fasting among the penances with which he chastised his body and kept it in subjection (2 Cor. 6:5 and 11:17; 1 Cor. 9:27).

The authors do not agree whether the Apostles commanded the fast of Lent. Although some Fathers, such as St. Jerome, say that Lent is observed according to the tradition of the Apostles (Ep. 27, 27, to Marcella), and indeed St. Peter Chrysologus affirms that it is observed by divine ordinance (Serm. 11), it seems nevertheless more probable the thesis of St. Augustine, who holds that Jesus Christ and the Apostles did not establish the days of fasting (Epist., 36, 14; PL 33, 151).

The Church introduced the observance of Lent before Easter Communion, and it was observed in East and West. In the Eastern Church, however, it lasted seven weeks, because every Saturday and Sunday was excluded, while in the Western Church it was for six weeks, the fast being interrupted only on Sunday. Toward the ninth century, the obligatory custom was introduced of beginning the fast four days before Lent, so that, excluding Sundays, there would be forty days of fasting.

Toward the fifth century, the custom was introduced of fasting for some days during the “Four Ember Days” of the year to consecrate the whole year to the Lord according to Hebrew usage, so much so that later the ordinations of priests and deacons could be held only during these “Four Ember Days.” In the sixth century, some Churches obliged to a three-day fast each week of Advent, and likewise the three days of the Rogations were introduced, which soon became a universal custom. At this time began the custom of fasting on the vigils of Christmas, Epiphany, the Assumption, and the feasts of the Apostles.

In the Eastern Church, a meal was often taken, though very scanty, while in the Latin Church after Vespers, i.e., almost at the end of the day, there was a single meal. During the fast, the faithful abstained not only from food but also from wine, and even water was permitted, to quench thirst, only at certain fixed hours. From the tenth century, the custom was introduced of taking the meal at three in the afternoon, and later it was moved to midday. Until the thirteenth century there was only one meal, then the evening meal was introduced. In the nineteenth century, the custom began of taking a little coffee in the morning with a very limited portion of bread.

### III. Subject and Time of Fasting

All are bound to moral fasting. With regard to Eucharistic fasting (v. COMUNIONE EUCARISTICA; MESSA), all those who must celebrate Holy Mass or receive Communion are bound from midnight until after Communion, unless they have obtained a dispensation, except in the case of viaticum. Here, only ecclesiastical fasting is treated, to which all baptized persons are bound by the general law of the Church from the completion of their 21st year to the end of their 59th year (can. 1254 § 2; for computation, V. can. 34 § 2), on the days of Lent (from Ash Wednesday until noon on Holy Saturday, excepting Sundays), on Wednesdays, Fridays, and Saturdays of the "Quattuor Tempora"; on the vigils of Christmas, Pentecost, the Assumption, and All Saints, unless these fall on a Sunday or a holy day of obligation (can. 1252 § 4). During the days of Lent, excepting Fridays and Saturdays, only the law of fasting applies; on the other days, including Fridays and Saturdays of Lent, the law of fasting is joined with that of abstinence (can. 1252 § 3).

Fasting is also commanded on the vigil of the consecration of a church to the consecrating bishop and to those who request the consecration of the church (can. 1166 § 2). These are: the one who has built the church at his own expense, if he requests its consecration; all the canons composing the Chapter, if it is they who request the consecration; the parish priest, if he at least implicitly requests it (S. Congregazione del Concilio, July 3, 1909); but not the people or the church council, since they have no right in spiritual governance; nor probably the assistant priests (unless they expressly request it), because the aforementioned can. 1166 § 2 departs from the Roman Pontifical, which required the fasting of the clergy and the people.

The days of abstinence and fasting are considered sacred time (can. 1243). To establish, transfer, or abolish them is a task reserved to the supreme ecclesiastical authority (can. 1244 § 1). Ordinaries may, however, by way of an indirect act, establish days of fasting and abstinence for their dioceses.

### IV. The Essence of Fasting

There is no authentic declaration of the Church that determines the essence of ecclesiastical fasting.

Ancient authors placed the essence of fasting in three conditions, namely: a) in the single meal; b) in the fixed hour of this meal; c) in the fixed abstinence from certain foods such as meat and dairy products. According to modern authors, these three conditions pertain to the perfection of fasting but do not constitute its essence. What has remained unchanged through the disciplinary changes of the Church is the principle of the single principal meal.

1. **Single or Principal Meal.** – The duration of a fasting day is reckoned from midnight to midnight. Within this time, only one complete meal is permitted (can. 1254 § 1); if, for any reason, another equal meal is taken, fasting becomes impossible, and the precept is violated gravely. Custom has indeed added two other small meals, the morning "frustulum" and the evening "coena," but these are subject to various restrictions regarding the quality and quantity of food. For the principal meal, however, there is no fixed quantity of food beyond which the fast is violated. Even one who eats lavishly or exceeds the bounds may sin against temperance, may lose the entire or partial merit of fasting, but does not violate the precept of fasting. The same applies to quality. On days of fasting alone: a) meat is not excluded (which was once controversial before the CIC); b) mixing meat with fish is not prohibited (though it was in antiquity). The time at which the principal meal must be taken during the fasting day is not strictly determined, despite ancient customs and disputes among ancient authors. Custom in our countries generally places the principal meal at midday, around noon. However, the meal may be inverted, with the evening meal taken in the morning, or the morning meal taken in the evening, followed by the principal meal at noon and a small breakfast in the evening (can. 1251 § 2). Some determination exists regarding the duration of the principal meal. It is generally admitted that the meal may not be prolonged beyond two hours without fault, except for a just cause, such as the custom of extending the time when guests are present. The meal must be morally continuous, as a notable interruption would lead to multiple meals, which is not permitted. The determination of interruption is to be made according to a more moral than mathematical computation, taking into account the intention of the faster, as well as the length of the interruption. Interruption is generally considered not notable within half an hour; but if one has legitimately interrupted, even an interruption of an hour does not prejudice the fast, and the meal may lawfully be continued.

2. **Breakfast or Morning Meal and Evening Meal.** – At present, even on fasting days, it is permitted to take a little food in the morning, that is, a small quantity of coffee, chocolate, and similar items with a bit of bread, sweets, fruit, or a quantity of nutritious food, except meat (Pontifical Commission for Interpretation, Oct. 29, 1919). The permitted quantity is about 60 grams (S. Penit., Nov. 21, 1843), unless one's constitution or duties require something more.

In the evening, a modest meal is now permitted, according to the quantity and quality of food (excluding meat and meat broth) permitted by local custom.

Regarding quantity, one may take as much as is necessary to suitably fulfill one's duties; but in general, the quantity permitted by theologians is from 250 to 300 grams, or, by another computation, one-fourth of a full meal.

On the vigil of Christmas, universal custom permits double the usual quantity on fasting days.

Custom, generally expressed in diocesan acts and the practice of good faithful, indicates, as mentioned, the quality of permitted foods. In many places, dairy products and eggs are permitted.

Pilgrims may certainly follow local customs regarding quantity and quality. Indeed, according to some, they may even follow the more lenient customs of their domicile, provided scandal is avoided.

3. **Dispensation.** – The obligation of fasting ceases if dispensed by the legitimate superior. Often the cause itself is not sufficient to excuse from fasting, but it is sufficient to request a dispensation from the superior, especially since the obligation of the law depends on the superior's will, who, if he deems it, can remove such a bond. The dispensation may be granted for fasting alone, for abstinence alone, or for both.

4. *Author of the dispensation.* – In the Church, the following may dispense from fasting:
a) the Pope, who always dispenses *validly*, and if there is a just cause also *licitly* (if there is no just cause, this would amount to favoritism or partiality);
b) the Ordinary of the diocese in individual cases or for individual families; however, he may dispense the entire diocese for reasons of public health or for a large gathering of people. For the Ordinary to dispense not only licitly but also validly, he must have a just cause (since he dispenses from the law of his superior); within the diocese, he may dispense all, but outside the diocese only his own subjects (can. 1245 § 1-2);
c) the parish priest may dispense all (including pilgrims) within the limits of the parish, but only individual faithful or individual families; outside the parish, he has the same faculty only for his own parishioners (can. 1245 § 1). A vicar who substitutes for an absent parish priest or is delegated by him—even if the parish priest is present—may also dispense individual faithful or individual families;
d) superiors of a clerical exempt religious institute have the same faculty as the parish priest (to dispense in individual cases) with regard to professed members, novices, and all those who, for reasons of service, education, hospitality, or illness, reside in the religious house for a full day (it is sufficient to have the intention of remaining for such a time; can. 1245 § 3);
e) delegates within the limits of their delegation.

5. *Confessors,* unless they have been delegated, physicians, and superiors of religious women may not dispense, but they may declare whether in a given case there is a cause excusing from fasting.

VI. *MORAL OBLIGATION.* – The law of fasting is a positive precept and binds under pain of mortal sin for those who are bound by it, unless they have some excusing cause. On 24 September 1665, Alexander VII condemned the following proposition: “Whoever violates the fasting to which he is bound does not sin mortally, provided he does not act out of contempt or disobedience, e.g., because he does not wish to submit to the precept” (Denz-U, no. 1123). Invincible ignorance, complete inadvertence, or forgetfulness excuse from formal sin.

Giuseppe Sima

VII. *ACTUALITY OF THE LAW ON FASTING.* – After what has been said and reported, a consideration naturally arises: why is there still a law on fasting when its observance in practice, already objectively, due to a combination of circumstances, is very limited; and, moreover, the precept itself is often neglected by the faithful?

XLI. *ACTUALITY OF THE LAW ON FASTING.* – After what has been said and reported, a consideration naturally arises: why is there still a law on fasting when its observance in practice, already objectively, due to a combination of circumstances, is very limited

compliance with the law. All this prevents the introduction of a custom contrary to the law.

Moreover, in the extraordinarily adverse circumstances produced by the war, the supreme legislator (Apostolic Indult of 19 December 1941, AAS, 33 [1941], p. 516) felt a paternal need to ease the law on abstinence and fasting, but did so by granting to Ordinaries, in the manner of a general indult, the faculty to dispense within the territory of their jurisdiction, while at the same time maintaining the observance of the law for Latin-rite faithful on Ash Wednesday and Good Friday and for faithful of other rites on two days to be determined by their own Ordinaries.

More recently (Sacred Congregation of the Council, 28 January 1949), in view of the improved circumstances, the law on abstinence and fasting has been partially restored, with the faculty granted to Ordinaries being limited as follows:
a) abstinence is to be observed on all Fridays of the year;
b) abstinence and fasting are to be observed on Ash Wednesday, Good Friday, and the vigils of the Assumption and of Christmas; on these days, however, Ordinaries are granted the faculty to permit the use of eggs and dairy products even in small morning and evening meals (AAS, 41 [1949], pp. 32-33).

In these two decrees, while leaving Ordinaries free to avail themselves or not of these faculties, the Holy See has always recommended that the granting of the indult be accompanied by the recommendation to compensate for the lack of corporal mortification with exercises of Christianization and charity. All this leads to a fundamental consideration.

The Church, despite the fact that not a few wish to dismiss the law on fasting as impracticable, is in fact very zealous regarding II. One might think that it is merely the weight of long tradition that determines this, but the reason is in fact deeper.

The fasting prescribed by the Church is an act of public and social worship. It is not the isolated faithful who mortifies himself; it is the Church itself that is spiritualized, purified, by establishing and ordering this special means of purification. Moreover, it is intimately connected with the spiritual and social life of the faithful. During Lent, fasting is the object of all the most beautiful liturgical prayers; the faithful are bound or at least exhorted to abstain from amusements and to attend to the word of God; even today, though less than in the past, civil life itself is aware that Lent is a sacred time for all.

To remove ecclesiastical fasting and leave only the moral and natural duty of mortification would be highly detrimental to the life of the faithful, for many would then practically be led to disregard corporal mortification altogether.

Now, in this positive precept, the Church has established the general norms for the observance of fasting, because, being imposed on the entire community of the faithful, it must also have a common external manifestation.

Within this norm, however, the faithful must truly love the mortification of their flesh and spirit.

of our possibilities. Fasting for a year is common
both in invertebrates and in lower vertebrates. Thus,
a leech, for example, can fast for a year or more after
completely exhausting its blood reserve, of which it
remembers its own digestive tract every time it finds
itself able to suck; not to mention the *Argas reflexus*,
which, after an abundant blood meal, can fast for up
to seven years. Similar durations are also observed
among vertebrates: cases are cited of snakes surviving
even two years of fasting. Resistance, however, is
markedly lower in homeotherms, in which adaptation
to a body temperature higher than the ordinary
environmental temperature entails the need for active
combustion to counter the continuous loss of heat
through radiation. In this regard, the maximum duration
of fasting varies considerably from species to species,
depending precisely on the extent of such radiation,
and can, in fact, be considered inversely proportional
to the linear dimensions of the animal. When one
considers that smaller dimensions correspond to a
body surface that is smaller in absolute value but
greater in relative value—i.e., relative to the unit of
volume and thus of weight—it is easy to understand
why small animals exhibit much greater thermal
radiation than large ones and are therefore endowed
with a much more intense metabolism and, consequently,
possess far lower resistance to fasting.

Special conditions apply to hibernating mammals
(e.g., marmots), in which fasting can last much longer
than would otherwise be expected, because here an
additional adaptation allows the animal to survive a
drop in body temperature of several degrees.

For humans, the few reliably documented data suggest
that the maximum duration of fasting is around
70 days, a value somewhat lower than would be
predicted based on the relationship with linear dimensions.

During fasting, once the last residues in the digestive
tract are exhausted, the organism turns to its reserves.
First and foremost, the glycogen in the liver, which
rapidly disappears; then that in the muscles. Later,
the fat stored in the subcutaneous adipose panniculus
and in the intervisceral cushions comes into play. Moreover,
with the onset of inanition, the metabolic rate curve
also declines; although the data on this point are not
entirely consistent, it seems that this decline is not
simply attributable to the simultaneous decrease in
weight but, being more rapid than this, expresses a
particular adaptation by which the organism adjusts
the intensity of its metabolism to the special emergency
conditions in which it finds itself and the consequent
need for economy. In the case of humans, for example,
the production drops from 30.2 calories per kg of
weight on the first day to 17 calories on the forty-second.
At the end, a sudden rise in the metabolic curve—
of still obscure significance—fits into the picture of
those pathological phenomena that herald and accompany
the imminent end.

So far, we have spoken of the quintessential
dynamogenic foods, carbohydrates and lipids. With
regard to proteins, which, although usable for energy
purposes, are nonetheless the precious components
of protoplasmic structures, the initial rapid drop in
urinary nitrogen—which then remains at this level
for a long time—attests to the organism’s initial
adoption of a protein-economy regimen. Toward the
end, a sudden rise in the nitrogen excretion curve
reveals the involvement of proteins. Once the ternary
reserves are exhausted, it is their turn to fuel the last
spark of life. But by now we are in the realm of
pathological phenomena, when the organism is forced
to draw on the very constituents of its tissues. Yet
even in this final phase, autoregulatory mechanisms
continue to operate: the nervous system is the last
to remain intact, the last to lose weight. The first
to diminish, on the other hand, is the liver, which
may be related, not only to the quantity of reserves
it contains, but also to the fact that its paraclimatic
mass must be considered (judging from the results
of Remotti’s research) much larger than that
corresponding to the functional needs of a given
moment, so as to allow, from moment to moment,
the availability of resting territories.

As for the third category of foods—vitamins—once
the scant quantities still present in the tissues are
exhausted, the functional effects of their deficiency
will inevitably be felt. Indeed, prolonged fasting is
accompanied by a series of disturbances that cannot
be attributed simply to the quantitative lack of food
intake, but, very likely at least in part, to the definitive
cessation of certain metabolic processes, as, moreover,
are the disorders that today advise against the use of
overly severe diets even in severe intestinal afflictions.

After a more or less prolonged period, inanition—as
mentioned—leads to death. Muscular strength has
gradually waned and all functions have been depressed;
but in homeotherms, body temperature does not drop
until the last few days, while nervous excitability
diminishes and secretory activity is reduced to a
minimum. Autopsy reveals, in addition to the extreme
reduction of adipose tissue (97% on average) and
muscle mass (50%), degenerative or regressive changes
in various tissues, first and foremost the hepatic
parenchyma. The brain and heart are the areas that,
even from an anatomopathological standpoint, show
the latest alterations. However, death—which occurs
when the total weight loss reaches 40–50% (rarely
60%) of the initial value—cannot be attributed to the
total exhaustion of every material still fueling basal
metabolism. Other factors must be at play: toxic
phenomena, presumably arising from qualitative
changes in metabolism (consider the early acetonuria
in fasting animals, or, on the other hand, the importance
of water in prolonging resistance and mitigating
pathological manifestations), or profound functional
disturbances due to vitamin deficiency.

From what has been said so far, one might think
that fasting should be regarded solely as an abnormal
event in the body’s economy. Nothing could be
further from the truth. It is of the greatest interest
to find it normally interspersed in the life of many
species of widely differing systematic positions. In
these cases, it is not simply the deprivation of food
in hibernating forms, linked to the inertia and immobility
of lethargic states; rather, it is a far more striking
phenomenon: fasting that accompanies periods of
intense physiological activity. Thus, in holometabolous
insects, during the pupal stage, when the work of
renewal of almost all organ systems—destroyed and
then rebuilt—is at its height; thus in many teleosts,
during the laborious process of maturation of the
reproductive organs, accomplished at the expense of
muscle proteins; and thus again in the tadpoles of
anurans undergoing metamorphosis. Such a relationship,
observable in nature, is in a way corroborated by
experimental results that seem to indicate in fasting
a kind of “stimulating principle” for certain physiological
periods.

But its positive importance also emerges from the fact that, since ancient times, it has constituted a therapeutic and preventive practice, even in human hygiene and medicine. Apart from the rest it ensures to the entire digestive system—including the liver and pancreas—and thus, indirectly, also to the cardiovascular system relieved of the corresponding workload of muscular and glandular digestion (hence the excellent practice of inserting a day of fasting in the weekly diet), the fact that the cell finds itself in a deficit of food means it must also utilize products, alimentary substances that are inherent yet unmetabolized. This will involve a forced metabolism, compelling it to the deepest degradation and removal of a quantity of substances ordinarily stored as waste. Is this discharge of waste, this deeper “cleansing,” perhaps the factor behind that rejuvenation to which the above-mentioned experiences would lead one to think? On the other hand, in lipid deposits, the organism accumulates, together with reserve fat derived from alimentary excesses, also a considerable proportion of catabolites (waste) that remain sequestered there, so that adipose cushions can, in a certain sense, be compared to those storage kidneys found in a great number of invertebrates. And perhaps it is precisely the need to free the circulation from this waste that is one of the stimuli for adipogenesis; this explains the frequent onset of this process, independently of alimentary excesses and rather in relation to abnormal states of metabolism. And here is a new aspect of fasting that, by mobilizing such inert adipose deposits, also eliminates the mass of waste accumulated within them. One can thus understand what a precious therapeutic means fasting constitutes, provided it is applied with certain precautions designed to avoid dangers. First of all, it will be necessary to remove from the intestine those residues that the organism rapidly reabsorbs, along with the load of toxic products from the putrefaction of the intestinal bacterial flora that accompanies them.

It will be necessary to ensure, through an abundant supply of water, the normal water balance of the tissues and the normal work of the excretory organs for the removal of every type of toxin; to alternate fasting or phases of underfeeding, during which the “dirty fat” is removed, with phases of normal and intense feeding to recharge the organism with “clean fat,” ready to receive new waste.

Among the most diverse peoples and religions, fasting is widely practiced as a universal norm. One certainly does not wish to fall back into the crude materialistic error that, in this precept, sees nothing more than a happy physiological intuition of the legislator, who would have cloaked in spirituality a practice imposed by purely physical exigencies of climate and race, continuing, in the human species, as a voluntary exercise what, in a great number of animals, is the result of instinct and the ordinary functional rhythm. The value of fasting, for man composed of body and spirit, is, once and for all, suggestively impressed in the few but incisive words: “Corporali ieiunio vitia comprimis, mentem elevas, virtutem largiris et praemia.” These words, while explicitly translating its spiritual resonances, implicitly also suggest its physiological sense, closely connected with the former. Elasticity, that is, and freshness of the body, which, through mysterious links, reverberate from the physiological sphere to that of the spirit; elasticity and freshness of mind and heart, the capacity to control the impulses of the one, to expand in elevation toward the other, in a freedom of movement unknown to an organism numbed and imprisoned in the suffocating invasion of its own metabolism. Youth, in a word, youth of body and spirit, which is far less the enviable privilege of a fleeting age than the lasting fruit of a conquest strongly willed and firmly defended.