It is better not to eat, than to eat and not pray. It is customary to pray Our Lord’s Prayer, without adding the priest’s part: “For Thine is the Kingdom…” or to pray another pious prayer that confesses the Incarnation and that reminds of us what we are doing…
The eyes of all hope in Thee, O Lord, and Thou givest them their food in due season. Thou openest Thy generous hand and fillest every living thing with good will.
If you also pray after meals, pray such a prayer as this:
We thank Thee, O Christ our God, that Thou has sated us with the good things of Thine earth: do not deprive us also of Thy heavenly Kingdom.
The fathers tell us not to eat until full, but stop while still a little hungry. Besides, the stomach does not tell the brain it is full, until about 20 minutes after it has had enough. Be willing to leave a little on the plate; it is not waste, rather waste is the energy lost on too much preoccupation with food.
Pray always “In the Name of the Father, and of the Son, and of the Holy Spirit.”
Pray the Jesus prayer at all times when the slightest need or inclination is felt, and at some times simply as a way of living, or as a discipline. Do not try to regulate your breathing or engage in any other ascetic exercise without consulting your Father Confessor.
— Catechetical Letter 4/16/05