Read the previous article: The Purpose of Fasting (Part 1)
“And the disciples of John and the Pharisees used to fast; and they come and say to him: Why do the disciples of John and of the Pharisees fast; but thy disciples do not fast? And Jesus saith to them: Can the children of the marriage fast, as long as the bridegroom is with them? As long as they have the bridegroom with them, they cannot fast. But the days will come when the bridegroom shall be taken away from them; and then they shall fast in those days” (Mark 2:18-20).
Fasting has been a part of the Catholic Church since the time of the Apostles, who instituted fasting shortly after our Redeemer’s Ascension into Heaven. Fasting in the Apostolic Age constituted two primary fasting periods: the weekly devotional fasts and the Lenten Fast.
In the early Church, fasting (which included abstinence as part of it) was widely observed each week on Wednesday and Friday. This practice is still kept by some pious Catholics and Eastern Catholics.
The Didache, also known as ‘The Lord’s Teaching Through the Twelve Apostles to the Nations,’ written by the end of the first century, states in chapter 8: “But let not your fasts be with the hypocrites; for they fast on the second and fifth day of the week; but fast on the fourth day and the Preparation.”
Since Sunday is the first day of the week, the fourth day referred to Wednesday and the day of Preparation referred to Friday. The phrase “day of preparation” (or, “parasceve”), which refers to the day preceding the Sabbath on Saturday, is found in the Scriptures in Matthew 27:62; Mark 15:42; Luke 23:54; and John 19:14,31,42. All such instances unequivocally confirm that it refers to Friday.
On the rationale for fasting on these days, St. Peter of Alexandria, Patriarch of Alexandria until his martyrdom in 311 AD, explains: “On Wednesday because on this day the council of the Jews was gathered to betray our Lord; on Friday because on this day He suffered death for our salvation.” Likewise, the 1875 Catechism of Father Michael Müller adds: “This practice began with Christianity itself, as we learn from St. Epiphanius, who said: ‘It is ordained, by the law of the Apostles, to fast two days of the week.’”
Some places also added Saturday fasting, as noted by St. Francis de Sales who wrote, “The early Christians selected Wednesday, Friday and Saturday as days of abstinence.”
Saturday fasting eventually became extended to the entire Church in the early 400s by Pope Innocent I, who wrote: “Reason shows most clearly that we should fast on Saturday, because it stood between the sadness [of Good Friday] and the joy [of Easter Sunday].”
The Douay Catechism written in 1649 explains the rationale for Saturday abstinence, which was then still universally practiced even though observance of the weekly fast on Saturday had long ended by that time: “To prepare ourselves for a devout keeping of the Sunday, as also in honor of the blessed Virgin Mary, who stood firm in the faith on that day, the apostles themselves wavering.”
The Apostolic Origin of the Lenten Fast
The great liturgist Dom Gueranger (†1875) wrote that the fast which precedes Easter originated with the Apostles themselves:
“The forty days’ fast, which we call Lent, is the Church’s preparation for Easter, and was instituted at the very commencement of Christianity. Our blessed Lord Himself sanctioned it by fasting forty days and forty nights in the desert; and though He would not impose it on the world by an express commandment (which, in that case, could not have been open to the power of dispensation), yet He showed plainly enough, by His own example, that fasting, which God had so frequently ordered in the old Law, was to be also practiced by the children of the new…The apostles, therefore, legislated for our weakness, by instituting, at the very commencement of the Christian Church, that the solemnity of Easter should be preceded by a universal fast…”
The Catechism of the Liturgy by a Religious of the Sacred Heart affirms the apostolic origin of the Lenten fast: “The Lenten fast dates back to Apostolic times as is attested by Saint Jerome, Saint Leo the Great, Saint Cyril of Alexandria and others.” In the 2nd century, St. Irenaeus wrote to Pope St. Victor I inquiring on how Easter should be celebrated, while mentioning the practice of fasting leading up to Easter.
Initially the Lenten fast was practiced by catechumens preparing for their Baptism with a universal fast for all the faithful observed only during Holy Week, in addition to the weekly fasts that were devotionally practiced. But early on, the baptized Christians began to join the catechumens in fasting on the days immediately preceding Easter.
The duration of the fast varied with some churches observing one day, others several days, and yet others observing intensive 40-hour fasting, in honor of the forty hours that Our Lord spent in the sepulcher. By the third and fourth centuries, the fast became forty days in most places. St. Athanasius, in 339 AD, referred to the Lenten fast as a forty-day fast that “the whole world” observed.
Shortly after the legislation of Christianity in the Roman Empire, the bishops at the Council of Nicea in 325 AD fixed the date of Easter as the first Sunday after the first full moon after the vernal equinox. The canons emerging from that council also referenced a 40-day Lenten season of fasting.
The Lenten fast was not a merely devotional fast but one of precept under penalty of sin. Father Stephen Keenan’s Catechism from 1846 quotes St. Augustine (who lived from 354 – 430 AD) as saying: “Our fast at any other time is voluntary; but during Lent, we sin if we do not fast.”
One Meal a Day After Sunset
For the early Christians, the fast was kept until sundown, in imitation of the previous Jewish tradition. Dom Gueranger’s writings affirm: “It was the custom with the Jews, in the Old Law, not to take the one meal, allowed on fasting days, till sun-set. The Christian Church adopted the same custom. It was scrupulously practiced, for many centuries, even in our Western countries. But, about the 9th century, some relaxation began to be introduced in the Latin Church.”
Fasting included abstinence from meat, fish and all animal products (e.g., dairy and eggs). And notably in the early Church, fasting also included abstinence from wine, taking man back to the same diet that mankind practiced before God permitted Noah to eat meat and drink wine. For this reason, even in the Eastern Church today some fasting periods prohibit wine. As such, in apostolic times, the main meal was a small one, mainly of bread and vegetables.
While not as ancient as the Holy Week fast, the Advent fast originated in the early Church by at least the fourth century. The Catechism of the Liturgy describes the fast leading up to Christmas: “In a passage of St. Gregory of Tours’ History of the Franks we find that St. Perpetuus, one of his predecessors in the See, had decreed in 480 AD that the faithful should fast three times a week from the feast of St. Martin (November 11th) [up] to Christmas… This period was called St. Martin’s Lent and his feast was kept with the same kind of rejoicing as Carnival.” In historical records Advent was originally called Quadragesimal Sancti Martini (Forty Days Fast of St. Martin).
The Catechism of the Liturgy notes that this observance of fasting likely lasted until the 12th century. Remnants of this fast remained in the Roman Rite through the 19th century when Wednesday and Friday fasting in Advent continued to be mandated in most countries.
The Apostles Fast
The observance of a fast leading up to the Feast of Saints Peter and Paul also originated in the early Church under Pope St. Leo the Great around the year 461. At the time of St. Jerome, it was known as “Summer Lent,” though it was not practiced under obligation like the fast of Lent itself. While it subsequently fell out of observance in the Roman Catholic Church, the Eastern Catholic Church still observes this fast to some extent.
The Roman Catholic Church, though, maintained the summer Ember Days, in addition to the traditional fast on the Vigil of Saints Peter and Paul, until post-conciliar times. As a result, of the fasting that was originally practiced only a fragment persisted.
In the next article we will consider how fasting and abstinence considerably developed from the 5th through the 13th centuries. In our own spiritual lives, though, we can certainly adopt these ancient fasts as a means of making greater satisfaction for sin.
 By contrast, the traditional days for Jewish fasting were Thursdays and Mondays, on account of the Tradition that Moses went up Mount Sinai on a Thursday and returned on a Monday.
 This excellent catechism, published by The Paulist Press (New York, 1919) may be read at https://archive.org/details/familiarexplana00mlgoog
 Introduction to the Devout Life, III, Chapter 23.
 Epistola 25 ad Decentium 4; Patrologia Latina 20:555.
 Douay Catechism, Q. 554, “Why Abstinence on Saturdays?,” available for reading at https://archive.org/details/The1649DouayCatechismTubervilleHenryD.D.4515/page/n55/mode/2up
 This excellent older Catechism may be read at http://catholicsaints.mobi/ebooks/book-articles/catechism-of-the-liturgy-for-young-and-old.htm
 The Catechism of the Council of Trent on “The Sacrament of Baptism”.
 Weiser’s “Christian Feasts and Customs,” available at https://archive.org/details/WeiserChristianFeastsandCustoms/page/n187/mode/2up
 A Doctrinal Catechism by Fr. Stephen Keenan, p. 179, available for reading at http://www.catholicapologetics.info/apologetics/protestantism/catechism.htm
 On the prohibition against wine, Dom Gueranger wrote: “In the early ages of Christianity, fasting included also the abstaining from wine, as we learn from St. Cyril of Jerusalem [Catech. iv], St. Basil [Homil. i. De Jejunio], St. John Chrysostom [Homil. iv. Ad populum Antioch.], Theophilus of Alexandria [Litt. Pasch, iii], and others. In the West, this custom soon fell into disuse. The Eastern Christians kept it up much longer, but even with them it has ceased to be considered as obligatory.”
 Catechism of the Liturgy, Q. 111: “The custom of keeping Advent originated in the fourth century in the churches of the East. It was only towards the end of that century that the date of Christmas was fixed for December 25th.”
 Pope Leo I of Rome, Sermon 78: On the Whitsuntide Fast (https://www.ccel.org/ccel/schaff/npnf212.ii.v.xli.html) confirms the existence of this fasting period at least back to 461 AD.