Why do Catholics fast before Holy Communion?
In the Old Testament people fasted before coming into God’s presence or doing a special job for him. For example, Elijah fasted on the way to Mount Horeb to meet God. Moses fasted when he received the Ten Commandments. So we follow this tradition and fast before encountering Christ in the Eucharist. Fasting from food or drink one hour before receiving Holy Communion also creates a physical hunger and thirst and adds to our spiritual appetite for the Bread of Life.