Fasting

FASTING. - Fasting, from the ecclesiastical Latin iejunus, refers to one who is empty of food. The substantivized adjective eventually came to signify the practice of one who fasts, that is, the act of fasting.

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 Validity of the Law on Fasting

VIII. Fasting in Non-Christian Religions

IX. Fasting and Science.

I. NOTIONS

To fast, in the full meaning of the word, is to abstain absolutely from all food and all drink. Theologians have given this complete fast the name of natural fast. It is the fast that the Church prescribes from midnight onward for the priest who celebrates and for the faithful who intend to receive Holy Communion, and which is therefore also called Eucharistic fast.

This same fast is still highly recommended for the adult who is baptized and for the priest who baptizes him (can. 753 § 1, 808, 858 § 1).

The fast that one imposes upon oneself freely, 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 abstinence from food and drink according to a rational regimen. If the motives inspiring it are merely human, e.g., bodily health, physical well-being to study better, etc., then it is called philosophical. If the motives are supernatural, it is instead called Christian fast. This fast is inspired primarily by mortification and penance as a preventive measure against sin or as a means of satisfaction for sins committed.

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

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

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

Fasting is properly an act of the virtue of abstinence, a 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, also be commanded by other virtues: charity, religion, penance, chastity, etc.

Fasting is a useful good and therefore is not commanded for itself, but only in relation to the end to which it is useful. The utilities that can be obtained through the practice of fasting can ordinarily be achieved by other means as well, and therefore by natural law it is not absolutely commanded for all, but only for those to whom it is necessary and insofar as it is necessary for them.

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

Moreover, it is in accordance with reason to measure oneself in food (v. ASTINENZA). That matter should prevail over spirit, no one can desire or approve. Now, gluttony is, after lust, the strongest of the passions of the senses and often itself provides fuel and incentive to lust. It is therefore opportune that a precept, in given periods and recurrences, with its external observances, should 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 it subject to itself.

That the mortification of gluttony can constitute an act of religion and 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 united together figured among the most proper means of obtaining graces from God. Pietro Palazzini

II. FASTING IN THE BIBLE

Fasting is praised and even commanded in the Old Testament (Tob. 12:8; II Kings 12:16; Judg. 8:6; Joel 2:12; Esth. 14:2; II Macc. 12:12).

The Jews were obliged to fast on the 10th 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 appeased by mere external fasting without true penitence 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 the preaching of the Gospel; however, He did not impose a precept of fasting upon His disciples while they were with Him, also to contrast the exaggerations of the Pharisees, who had multiplied the days of fasting to excess (Lk. 18:12). Nevertheless, He announced to the disciples themselves that they would fast later (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 not infrequently fasted, especially in the election of God’s ministers (Acts 13:2-3; 14:22). St. Paul expressly places fasting among the penances with which he chastised his body and kept it in subjection (II Cor. 6:5 and 11:17; I Cor. 9:27).

Scholars do not agree on whether the Apostles commanded the Lenten fast. While some Fathers, such as St. Jerome, say that Lent is observed "according to the tradition of the Apostles" (Ep. 27, to Marcella), and St. Peter Chrysologus even asserts that it is observed by divine order (Serm. 11), the thesis of St. Augustine seems more probable: he holds that Jesus Christ and the Apostles did not establish the days of fasting (Epist., 36, 14; PL 33, 151).

The Church introduced the custom of Lent before Paschal Communion, and it was observed in both the East and the West. However, in the Eastern Church it lasted seven weeks, because it was interrupted every Saturday and Sunday, whereas in the Western Church it lasted six weeks, with fasting interrupted only on Sundays. Around the 9th century, the obligatory custom of beginning the fast four days before Lent was introduced, so that, excluding Sundays, there would be a fast of forty days.

Around the 5th century, the custom of fasting for several days during the "Ember Days" of the year was introduced, dedicating the entire year to the Lord according to Jewish practice, so much so that ordinations of priests and deacons could only take place during these "Ember Days." In the 6th century, some Churches imposed a fast of three days each week during Advent, and the triduum of the Rogations was also introduced, which soon became a universal custom. During this period, the custom of fasting on the vigils of Christmas, Epiphany, the Assumption, and the feasts of the Apostles began.

In the Eastern Church, a meal—though a very meager one—was often permitted several times, whereas in the Latin Church, after Vespers, that is, almost at the end of the day, there was only one 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 10th century, the custom of taking the meal at 3 p.m. was introduced, and later it was moved to noon. Until the 13th century, there was only one meal; afterward, an evening meal was introduced. In the 19th century, the custom of taking a little coffee with a very small portion of bread in the morning began.

III. SUBJECT AND TIME OF THE FAST

All are bound to moral fasting. Regarding the Eucharistic fast (v. COMUNIONE EUCARISTICA; MESSA), all who must celebrate Holy Mass or receive Communion are bound from midnight until after Communion, unless they have been dispensed and excepting the case of Viaticum. Here, only ecclesiastical fasting is treated, to which all the baptized are bound by the general law of the Church from the completed twenty-first year to the end of the fifty-ninth year (can. 1254 § 2; for computation V. can. 34 § 2), on the days of Lent (from Ash Wednesday until noon of Holy Saturday, excluding Sundays), on the Wednesday, Friday, and Saturday of the Ember Days; 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). On the days of Lent, excepting Friday and Saturday, only the law of fasting applies; on the other days, including the Fridays and Saturdays of Lent, the law of fasting is united with that of abstinence (can. 1252 § 3).

The fast is also commanded on the vigil of the consecration of a church for the consecrating Bishop and for those who request the consecration of the church (can. 1166 § 2). These are: the one who built the church at his own expense, if he requests its consecration; all the canons composing the Chapter, if it is the Chapter that requests the consecration; the parish priest, if he at least implicitly requests it (Sacred Congregation of the Council, 3 July 1909); but not the people or the fabric council, because 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 fast of the clergy and the people.

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 only per modum actus designate days of fasting and abstinence for their dioceses.

IV. ESSENCE OF THE FAST

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

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

1. Single or principal meal

The duration of a day of fasting is computed from midnight to midnight. Within this time, only one full meal is permitted (can. 1254 § 1); if for any reason another equal meal is added, the fast becomes impossible, and the precept is violated in a grave matter. Custom has indeed added two other small meals, in the morning (frustulum mattutinum) and in the evening (cavula vespertina); however, these are subject to various restrictions regarding the quality and quantity of food. For the principal meal, there is no determined quantity of food beyond which the fast is violated. Even one who eats lavishly or excessively may sin against temperance, may lose entirely or partially the merit of the fast, but does not sin against the precept of fasting. The same applies to quality. On days of fasting alone: a) meat is not excluded (which was controversial before the CIC); b) it is not forbidden to mix meat with fish (though this was anciently prohibited). The position that the principal meal must occupy in the day of fasting is not strictly determined, notwithstanding ancient customs and the disputes of ancient authors. Custom in our countries ensures that the principal meal is lunch, usually taken around midday. However, one may also invert lunch with the evening meal or take the evening meal in the morning, then lunch at midday, and the morning meal in the evening (can. 1251 § 2). Some determination exists regarding the duration of the principal meal. It is unanimously admitted that one cannot, without fault, prolong the meal beyond two hours, 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 the interruption is to be made according to a more moral than mathematical computation, considering the intention of the one fasting, as well as the more or less lengthy interruption. The interruption, in general, is considered of no notable significance within half an hour; but if one has interrupted legitimately, even an interruption of an hour does not prejudice the fast, and thus one may licitly continue the meal.

2. Breakfast or morning meal and evening meal or supper

Currently, even on fasting days, it is permitted in the morning to take a little food, that is, a small quantity of coffee, chocolate, and the like with a little bread, sweets, fruit, or a quantity of nutritious food, except meat (Pontifical Commission for Interpretation, 29 Oct. 1919). The permitted quantity is approximately 60 gr. (S. Penit., 24 Nov. 1843), unless one’s constitution or duties require something more.

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

Regarding quantity, one may take what is necessary to suitably fulfill one’s duties; but in general, the quantity, considered in kind, permitted by theologians ranges from 250 to 300 gr., or, by another computation, one-fourth of a full meal may be considered permissible.

On the vigil of Christmas, universal custom allows a quantity double that of the usual fasting days.

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

Pilgrims may certainly follow local customs regarding quantity and quality. Indeed, according to some, they may also follow the more favorable customs of their domicile, avoiding scandal.

3. Matter not injurious to the law of fasting. - No liquid breaks the fast, that is, anything taken as a drink to quench thirst, aid digestion, or as medicine.

The violation of the fast may be substantial or accidental. The fast is substantially violated when one takes such a quantity of food that it equals another full meal or repast. If done knowingly, one sins gravely; if done through ignorance, inadvertence, or forgetfulness, there is no sin, but the fast no longer exists for that day.

The accidental violation of the fast occurs when something is taken as food, but the essence of the fast still remains; it is commonly admitted that a quantity of 130 gr. of food constitutes a grave accidental violation, whether taken at one time or in several instances (v. VIZI). However, if taken at different times, the more common doctrine holds that a greater quantity than 130 gr. is required.

In the case of a negative doubt about having violated the fast, the obligation of fasting substantially remains; in the case of a positive doubt, according to the norm of probabilism, one is no longer bound.

V. FASTING

Three causes excuse from fasting: moral impossibility, arduous labor, and dispensation.

1. Moral impossibility. — Every positive law, provided it does not concern something intrinsically evil or cause common harm or extreme spiritual damage to someone, does not oblige under grave inconvenience, whether physical or moral.

2. Arduous and continuous labor for several hours. — This does not refer only to manual labor but also to intellectual work. Therefore, if fasting would prevent the fulfillment of one’s duties or force their execution with great effort or physical weakness, one is not obliged to observe the fast.

Those excused due to heavy labor include peasants, blacksmiths, carpenters, masons, stonecutters, shoemakers, weavers, porters, etc. Custom also excuses those engaged in less strenuous work, such as printers, soldiers, domestic servants, shepherds, painters, fishermen, hunters, etc.—that is, those who work almost the entire day in fields, workshops, or industrial arts. Although professionals in the liberal arts are not per se excused, they too are exempt from fasting if they devote great effort to their disciplines, whether studying many hours a day or practicing their profession, especially if they have a weak constitution—thus judges, lawyers, professors, students, etc. Confessors who must hear confessions for seven or eight hours a day, preachers or missionaries who deliver sermons almost daily (if it involves great fatigue in preparation or delivery), are excused from fasting. So too are public employees who work approximately nine hours a day. Finally, travelers are excused when the journey entails considerable inconvenience.

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 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 appropriate, may remove such a bond. The dispensation may be granted for fasting alone, abstinence alone, or both.

4. Author of the dispensation. — In the Church, those who may dispense from fasting are:
a) The Pope, who always dispenses validly and, with just cause, also licitly (lacking a just cause would imply acceptance or preference of persons);
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 a great gathering of people. The Ordinary, to dispense not only licitly but also validly, must have a just cause (since he dispenses in the law of the superior); within the diocese, he may dispense all, but outside the diocese only his 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 parishioners (can. 1245 § 1). Even the vicar who replaces the absent parish priest or is delegated by him—even if the parish priest is present—may dispense individual faithful or individual families;
d) Superiors of an exempt clerical religious institute have the same faculty as the parish priest (to dispense in individual cases) regarding professed members, novices, and all those who, for reasons of service, education, hospitality, or illness, reside in the religious house for an entire day (it suffices to intend to remain for that time; can. 1245 § 3);
e) Delegates within the limits of their delegation.

Confessors (unless delegated), physicians, and superiors of religious women cannot dispense but may declare whether, in a given case, there is a cause excusing from fasting.

BIBL.:
A. Vermeersch, Theologiae moralis principia, II, Roma 1945, nn. 356-360; F. Cappello, De sacramentis, I, Roma 1944, nn. 412-415; P. Palazzini, Dizionario di teologia morale, Roma 1954, V. Digiuno; A. Sabetti, Theologia moralis, Roma 1948, nn. 580-585; G. Vromant, De religione et cultu, Bruges 1945, nn. 280-285.
— A. VERMEERSCH

VI. MORAL OBLIGATION

The law of fasting is a positive precept and obliges under pain of mortal sin for those who are bound to it, unless they have some excusing cause. On 24 September 1665, Alexander VII condemned the following proposition: «Chi viola il d. ecclesiastico a cui è tenuto, non pecca mortalmente, purché non lo faccia per disprezzo o disubbidienza, p. es., perché non vuole assoggettarsi al precetto» (Denz-U, n. 1123).

Invincible ignorance, complete inadvertence, or forgetfulness excuse from formal sin. Giuseppe Sima
VII. PRESENT RELEVANCE OF THE LAW ON FASTING — After all that has been said and reported, a consideration naturally arises: why does the law on fasting still exist when its concrete observance, already objectively limited by a confluence of circumstances, is further diminished by the faithful’s neglect of the precept itself?

The reason for this phenomenon has been sought in the decline of faith and Christian spirit, and it must be admitted that this has indeed had a significant influence. However, it is necessary to recognize that this is not the only cause. Cases of physical or moral impossibility are far more frequent than theologians have anticipated. In light of these considerations, many expected a mitigation of the law at the time of the Code’s promulgation, which did not occur. Nevertheless, desiring such mitigation, efforts were made to introduce it (cf. Ami du clergé, 1921; Ephémérides theologiae Lavandenses, 4 [1927], pp. 207-11). Yet even after the CIC, despite attempts to establish a contrary custom, this mitigation could not be achieved due to insufficient time for its introduction. All the more reason, then, to reject what is often repeated though rarely written: that the law on fasting no longer obliges because only a few observe II. This reasoning, writes Merkelbach (Summa theol. mor., 5th ed., II, Paris 1947, p. 897, n. 954, note 1), is insufficient, for the law has not become harmful or contrary to reason. Indeed, every year during Lent, dioceses and churches habitually re-emphasize it; and the very dispensations that the faithful request presuppose the law’s persis-

tence. All this prevents the establishment of a custom contra ius.

Moreover, in the extraordinarily adverse circumstances produced by the war, the supreme legislator (Apostolic Indult of 19 Dec. 1941, AAS, 33 [1941], p. 516) felt the paternal need to alleviate the law of abstinence and fasting. However, this was done by granting Ordinaries, by way of a general indult, the faculty to dispense within their jurisdiction, while maintaining the observance of the law for the faithful of the Latin rite on Ash Wednesday and Good Friday, and for the faithful of other rites on two days to be determined by their own Ordinaries.

More recently (Sacred Congregation of the Council, 28 Jan. 1949), given the improvement of circumstances, the law of abstinence and fasting was partially reinstated, with the faculty granted to Ordinaries to dispense being limited as follows: 6) abstinence is to be observed on all Fridays of the year; 8) abstinence and fasting are to be observed on Ash Wednesday, Good Friday, and the vigils of the Assumption and Christmas. On these days, however, all Ordinaries are granted the faculty to permit the use of eggs and dairy products even in the small morning and evening meals (AAS, 41 [1949], pp. 32-33).

In these two decrees, while leaving it to the Ordinaries to avail themselves of these faculties or not, the Holy See has always recommended that the granting of the indult be accompanied by the exhortation to compensate for the lacking bodily mortification with exercises of Christian perfection and charity. All this leads to a fundamental consideration.

Despite the fact that many wish to abolish the law on fasting as impracticable, the Church remains highly zealous in its regard. One might think that this is merely the weight of a long tradition, but the reason is deeper.

The fast prescribed by the Church is an act of public and social worship. It is not the isolated faithful who mortify themselves, but the Church herself who spiritualizes and purifies herself, establishing and ordering this special mode of purification. Moreover, it is intimately connected with the spiritual and social life of the faithful. During Lent, fasting constitutes the object of all the most beautiful liturgical prayers; the faithful are obliged—or at least exhorted—to abstain from amusements and to frequent the word of God. Even today, though less than in the past, civil life itself reflects 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 induced to disregard bodily mortification altogether.

Now, the Church, in her positive precept, has established the general foundations 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, the faithful must truly love the mortification of their flesh and spirit.

In all religions, the practice of fasting is found either for a determined period of time, with complete abstention from eating and drinking (natural fast), or with limited consumption of certain foods and beverages (partial fast); for abstention from particular foods, V. ASTINENZA.

Fasting is called public if prescribed for the entire community, private if it depends on the will of individuals. Regarding the purpose it aims to achieve, fasting may be an exercise of penance or propitiation, or a rite of mourning intended to express grief. It may also be a preparatory rite for certain religious acts or special ceremonies. In this regard, the fast of the month of Ramadan (the ninth month of the Muslim lunar year) is recalled, consisting of absolute abstention from food, drink, smoking, and sexual relations from dawn to sunset. At times, fasting is a rite of purification in preparation for any act that puts man in communication with God, especially in the Communion of ritual food. Fasting also serves to place those who practice it in favorable conditions to procure visions and hallucinations.

Among primitive peoples, there exists the prohibition against using sacred animals or plants for profane food; among the Indians, Orphics, and Pythagoreans, who believed in metempsychosis, it was forbidden to consume any animate being. The abstention from impure animals should also be noted, not for hygienic reasons or disgust, but solely because it was believed they contained something contrary to the divine principle, or because they were thought to belong in some way to demonic powers. For this reason, among the Pythagoreans, there was a prohibition against oviparous animals, eggs, certain fish, and the fava bean among vegetables (Diog. Laert., Vita Pitag., 29, 33).

Regarding the origin of fasting, some have thought that grief over the loss of a relative may have led to the neglect of food, and in this way, fasting would have become a conventional sign of mourning in the cult of the dead. Others explain fasting as a fear of contagion, the abstention from objects or foods contaminated by contact with the dead. Still others have suggested that the practices of sobriety and temperance required by philosophers may have led to the idea of religious fasting. As an ascetic practice, it is prescribed in Orphism and by Pythagoras; as a preparatory rite for initiation or certain ceremonies, it is commonly practiced in the cults of Eleusis, Ceres, Mithras, Attis, and Cybele, for which fasting was observed on March 24. Apuleius prepared himself with ten days of fasting for magical practices. In Athens, fasting prepared for the festival of the Thesmophoria.

Regarding the first of the three proposed questions, that of duration, the answer varies greatly depending on the species, or rather, on the different characteristics of their metabolism. As is easily foreseeable, organisms with sluggish metabolism, such as all heterotherms, exhibit the greatest resistance to fasting due to their lower consumption of energy-producing materials and slower wear. This resistance can reach truly surprising durations when compared to our own capabilities. Fasts lasting a year are common among both invertebrates and lower vertebrates. For example, a leech can remain fasting for over a year after completely exhausting its blood reserve, which it fills its digestive tract with each time it feeds. Even more remarkable is the case of Argas reflexus, which, after an abundant blood meal, can fast for up to seven years. Similar durations occur in vertebrates: cases of snakes surviving up to two years of fasting have been reported. Resistance decreases significantly in homeotherms, where adaptation to a body temperature higher than the average ambient temperature requires active combustion to compensate for continuous heat loss through radiation. Consequently, the maximum duration of fasting varies considerably from species to species, depending on the extent of such radiation, and can, in fact, be considered inversely proportional to the animal's linear dimensions. Given that smaller dimensions correspond to a body surface that is smaller in absolute value but larger in relative value—i.e., per unit of volume and thus weight—it is understandable that small animals experience much greater thermal radiation than large ones. They therefore have a much more intense metabolism and, correspondingly, far lower resistance to fasting.

Hibernating mammals (e.g., marmots) present particular conditions, in which fasting can last much longer than expected. This is due to an additional adaptation that 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 what might be predicted based on the relationship with linear dimensions.

During fasting, once the last residues in the digestive tract are exhausted, the organism begins to draw on its reserves. The first to be used are carbohydrates, particularly liver glycogen, which rapidly disappears, followed by muscle glycogen. Subsequently, the fat accumulated in the subcutaneous adipose layer and intervisceral pads is mobilized. However, with the onset of starvation, the metabolic intensity curve also declines. Although data on this are not entirely consistent, it seems that this decline cannot be simply attributed to the concurrent weight loss. Instead, it occurs more rapidly, reflecting a particular adaptation by which the organism adjusts the intensity of its metabolism to the emergency conditions in which it finds itself, and to the consequent need for economy. In humans, for example, caloric production drops from 30.2 calories per kg of body weight on the first day to 17 calories on the forty-second day. At the end, a sudden rise in the metabolic curve, the significance of which remains unclear, is part of those pathological phenomena that herald and accompany the imminent end.

So far, we have discussed the primary energy-producing nutrients, carbohydrates and lipids. As for proteins, which, though also usable for energy, are the precious components of protoplasmic structures, the rapid initial decrease in urinary nitrogen—later maintained at this level—demonstrates how the organism initially adopts a protein-sparing regimen. Toward the end, a sudden rise in the nitrogen excretion curve reveals the mobilization of proteins. Once the ternary reserves are exhausted, proteins now fuel the last flicker of life. However, this occurs within the realm of pathological processes, when the organism is forced to attack the very constituents of its tissues. Nevertheless, the autoregulatory capacity still directs this final phase: the nervous system is the last to remain intact and the last to lose weight. The liver, on the other hand, is the first to shrink, which can be attributed not only to the quantity of reserves it contains but also to the fact that its parenchymal mass (as indicated by Remotti's research) is much greater than what would correspond to the functional demands of any given moment, allowing for a continuous availability of resting territories.

As for the third category of nutrients—vitamins—once the small quantities present in the tissues are exhausted, the functional effects of their deficiency will become apparent. Indeed, prolonged fasting is accompanied by a series of disorders that cannot be attributed solely to the quantitative lack of food intake but, in all likelihood, at least in part, to vitamin deficiency. This is also evident in those disturbances that today advise against the use of overly strict diets even in severe intestinal conditions.

After a more or less prolonged period, starvation inevitably leads to death. Muscular strength gradually weakens, and all functions become depressed. In homeotherms, however, body temperature does not drop until the last few days, while the excitability of nervous elements diminishes, and secretory activity is reduced to a minimum. Autopsy reveals, in addition to extreme reduction of adipose tissue (97% on average) and muscle mass (50%), degenerative or reductive changes in various tissues, primarily the hepatic parenchyma. The brain and heart are the areas that, even from an anatomopathological perspective, show alterations later. Nevertheless, death—which occurs when the total weight loss reaches 40-50% (rarely 60%) of the initial value—cannot be attributed to the complete exhaustion of all materials still fueling basal metabolism. Other factors must be the immediate causes: toxic effects, likely due to qualitative alterations in metabolism (consider the early acetonuria in fasting animals, or, conversely, the importance of water in prolonging resistance and mitigating pathological manifestations), or profound functional disturbances from vitamin deficiency.

From what has been said so far, it might seem that fasting (digiuno, hereafter abbreviated as d.) should be considered solely as an abnormal occurrence in organic economy. Nothing could be more inaccurate. It is a fact of extreme interest to find it normally intercalated in the life of many species of vastly different systematic positions. In these cases, it is not merely the simple deprivation of food in hibernating forms, correlated with the inertia and immobility of lethargic states; rather, it is a far more suggestive phenomenon: a d. that accompanies periods of intense physiological activity. Thus, in holometabolous insects during the pupal stage, when the work of renewing nearly all organic systems—destroyed and then rebuilt—is at its greatest; thus, in many teleost fish during the laborious process of reproductive organ maturation, accomplished at the expense of muscle proteins; and again, in the tadpoles of anurans undergoing metamorphosis. Such a relationship, observable in nature, is in some way corroborated by experimental results that seem to indicate in d. a sort 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 for the entire digestive system—including the liver and pancreas—and thus, indirectly, for the cardiovascular system, relieved of the corresponding burden of muscular and glandular work during digestion (hence the excellent practice of intercalating a day of d. in the weekly diet), the fact that the cell finds itself in a state of food deficit means the necessity of utilizing products that would otherwise remain inert and unmetabolized. This involves a forced metabolism, compelling the cell to the deepest degradation and removal of a quantity of substances ordinarily deposited as waste. Might this unloading of waste, this deeper "cleansing," be the factor behind that rejuvenation to which the aforementioned experiences would lead one to think? On the other hand, in lipid deposits, the organism accumulates—along with reserve fat derived from dietary excesses—also a considerable proportion of catabolites (waste) that remain sequestered there, so that adipose pads may, in a certain way, be compared to those storage kidneys found in a great number of invertebrates. And perhaps it is precisely the necessity of freeing the circulation from this waste that stimulates adipogenesis; this explains the frequent onset of adiposity independently of dietary excesses and rather in relation to anomalous states of metabolism. And here is a new aspect of d., which, by mobilizing such inert adipose deposits, also eliminates the mass of waste accumulated therein. In this way, one can understand what a precious therapeutic tool d. constitutes, provided it is applied with certain precautions to avoid its dangers. First, it will be necessary to remove from the intestine those residues that the organism rapidly reabsorbs, along with the toxic products of bacterial putrefaction in the intestinal flora that accompany them.

It will be necessary to ensure, with an abundant supply of water, the normal water balance of the tissues and the normal function of the emunctories for the removal of all types of toxins; to alternate d. or phases of undernourishment, during which "dirty fat" is eliminated, with phases of normal and intense nourishment to recharge the organism with "clean fat," ready to receive new waste.

Among the most diverse peoples and religions, d. is widely applied as a universal norm. It is certainly not the intention to fall back into the narrow materialistic error that, in such a precept, sees nothing but a fortunate 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 fruit of instinct and ordinary functional rhythm. The value of d., for man made 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 expressing its spiritual resonances, implicitly suggest its physiological meaning as well, intimately connected with the former. That is, elasticity and freshness of the body, which, through mysterious bonds, reverberate from the physiological sphere to that of the spirit; elasticity and freshness of mind and heart, capacity for control over the impulses of the former, agile expansion toward the elevations of the latter, 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 strongly willed and firmly defended conquest.

Ettore Remotti