Indeed, we have seen that in the passion of gluttony, man delights in food outside of God–he considers it in and of itself and uses it only for his own pleasure. Since food is a creation of God (either directly or indirectly) and a gift of God to men, it has no value by itself but only through God, and is meant to be consumed Eucharistically. Thus, St Paul teaches that God “created [it] to be received with thanksgiving by those who believe and know the truth.”
Man is healed of his passion and regains a virtuous attitude by the turning around of his attitude that led him to consider food in itself and have it serve his own pleasure to considering such food in God, linking it to Him and giving Him thanks for it. Thus St Paul advises: “So, whether you eat or drink, or whatever you do, do all to the glory of God.”
By consuming food in such a manner, man sanctifies it, and in it, the created cosmos which it represents. But above all, he simultaneously sanctifies himself, not only doing away with the barrier that gluttony erected between man and God, but also uniting himself all the more to God every time he gives Him thanks.
~Dr Jean-Claude Larchet (Therapy of Spiritual Illnesses, vol. 3, pp. 10-11)