2. Fasting for One Hour. By ancient tradition Christians abstain from profane food prior to receiving the sacred food of the Eucharist. Until the pontificate of Pope Pius XII the Eucharistic fast was from midnight. Pope Pius reduced it to three hours, and after Vatican II, Pope Paul VI reduced it to one hour. The current Code of Canon Law states,
1. One who is to receive the Most Holy Eucharist is to abstain from any food or drink, with the exception only of water and medicine, for at least the period of one hour before Holy Communion.
2. A priest who celebrates the Most Holy Eucharist two or three times on the same day may take something before the second or third celebration even if the period of one hour does not intervene.
3. Those who are advanced in age or who suffer from any infirmity, as well as those who take care of them, can receive the Most Holy Eucharist even if they have taken something during the previous hour.
The Eucharistic fast is before Holy Communion, not the Mass. It is a fast from food and drink, water is alright, as is medicine. The moral theology tradition teaches that to be food it must be a) edible, b) taken by mouth, and c) swallowed. In addition to breakfast, lunch and dinner, candies, breath mints, lozanges and anything that is put into the mouth to be dissolved or chewed meets these conditions once the dissolved contents are swallowed. Chewing gum does not break the fast, but it is disrespectful of the Sacred Liturgy and once the juice is swallowed the fast is broken. The tradition also teaches that the fast is strict - one hour, that is, 60 minutes. Given that until recently the fast was from midnight, this seems very little to ask of Catholics.