Canon 919 of the Code of Canon Law states, “One who is to receive the Most Holy Eucharist is to abstain from any food or drink, with the exception of water and medicine, for at least the period of one hour before Holy Communion.” Actually, this regulation merely reflects an ancient tradition in our Church, which is even rooted in Judaism. In Acts of the Apostles (13:2), we find evidence of fasting connected with the liturgy. A more normative practice of fasting before receiving Holy Communion appears throughout the Church after the legalization of Christianity in A.D. 313. St. Augustine attested to this practice in his own writings.
Granted, the specific requirements of the fast have changed over time. Prior to 1964, the Eucharistic fast began at midnight. Pope Paul VI on November 21, 1964 reduced the fast to a period of one hour.
This rule has two exceptions: First, if a priest celebrates more than one Mass on the same day, as oftentimes happens on Sunday, he is only bound to the one hour fast before the first Mass. The priest may eat and drink something to keep up his strength between Masses even though a full hour fast will not occur before the next reception of Holy Communion.
Second, those who are elderly (at least sixty years of age) or sick as well as their caretakers can receive Communion even if a full hour fast has not been fulfilled. For example people in the hospital are not in control of their own schedule and may be eating or have just finished eating when visited by the Priest or Eucharistic Minister. Therefore, the period of fast before receiving Holy Communion is reduced to “approximately one quarter of an hour” for those who are sick at home or at a medical facility, those elderly confined to home or a nursing home, and those who care for these people and who are unable conveniently to observe the fast (Immensae Caritatis).
The most important point regarding this question concerns why we ought to fast. St. Paul reminds us, “Continually we carry about in our bodies the dying of Jesus, so that in our bodies the life of Jesus may also be revealed” (II Corinthians 4:10). We too are charged to convert our whole lives– body and soul– to the Lord. This conversion process involves doing penance– including bodily mortification like fasting– for our sins and weaknesses, which in turn strengthens and heals us. Pope Paul VI exhorted the faithful in his apostolic constitution Paenitemini, “Mortification aims at the ‘liberation’ of man, who often finds himself, because of concupiscence, almost chained by his own senses. Through ‘corporal fasting’ man regains strength, and the wound inflicted on the dignity of our nature by intemperance is cured by the medicine of a salutary abstinence.”
Moreover, the fast before receiving Holy Communion creates a physical hunger and thirst for the Lord, which in turn augments the spiritual hunger and thirst we ought to have. In the Old Testament, fasting prepared individuals to receive the action of God and to be placed in His presence. For instance, Moses fasted 40 days atop Mount Sinai as he received the Ten Commandments (Exodus 34:28), and Elijah fasted 40 days as he walked to Mount Horeb to encounter God (I Kings 19:8). Similarly, Jesus Himself fasted forty days as He prepared to begin His public ministry (Matthew 4:1ff) and encouraged fasting (Matthew 6:16-18). Likewise, this corporal work enhances the spiritual disposition we need to receive Christ in the Blessed Sacrament. In a sense, we fast so as not “to spoil our appetite” but to increase it for the sharing of the Paschal Banquet. Jesus said in the Beatitudes, “Blest are they who hunger and thirst for holiness; they shall have their fill” (Matthew 5:6). In all, fasting is an exercise of humility, hope, and love– essential virtues in preparing ourselves to receive the Holy Eucharist.
This regulation, however, does not mean we have to be scrupulous and count-off seconds. I remember once I concelebrated Mass with a priest who had eaten one-half hour before Mass and was worried that he would not have a one-hour fast before receiving Holy Communion. He literally set his watch for one-hour, dragged-out the prayers, and stood at the altar while I finished giving everyone else Holy Communion until the hour had ticked away. While we do not want to be lax, we do not need to be scrupulous. The goodness of receiving Holy Communion supersedes the precise “hour of fast” if there is a doubt.
However, note that one should also not be lax. Pope John Paul II lamented in Dominicae Cenae the problem of some people not being properly disposed to receive Holy Communion, even to the point of being in a state of serious mortal sin. He said, “In fact, what one finds most often is not so much a feeling of unworthiness as a certain lack of interior willingness, if one may use this expression, a lack of Eucharistic ‘hunger’ and ‘thirst,’ which is also a sign of lack of adequate sensitivity towards the great sacrament of love and a lack of understanding of its nature.” We must make a good faith effort to prepare ourselves properly to receive the Lord.
Therefore, the Eucharistic fast assists us in preparing to receive Holy Communion wholly– body and soul. This physical mortification strengthens our spiritual focus on the Lord, so that we may humbly encounter the divine Savior who offers Himself to us.