The holy angels have no bodies. They “feed on” truth, on God, by gazing upon Him with their purely spiritual minds.
We human beings, on the other hand, feed on truth and bread, since we have souls and bodies. We need both truth and bread to survive and thrive. Without this nourishment, we perish.
God feeds on nothing other than Himself; He possesses infinite life. He is obviously immortal—He’s eternal, the eternal source of all life–spiritual life and material life.
We understand from Holy Scripture that God formed mankind from the dust of the earth for the sake of giving us immortal life. Originally He made us to feed on the truth, and on the material largess of the earth–without ever experiencing the disintegration of the flesh.
But we disobeyed His law and fell away from the eternal source of life, leaving us to face the struggle to survive and the dissolution of our bodies back into dust.
God, infinitely merciful, became a man Himself, to unite our flesh with His life-giving power. He underwent our bodily death in His flesh. Then He conquered that death, rising again to a life no longer limited in any way by struggle or impending death.
But that’s not all: His work of uniting His death-conquering life with our flesh included the institution of the Mass and the Church. By instituting the Mass He instituted the Church, and vice-versa. The Mass is the life of the Church.
And the Mass is the way, perfectly suited to our human nature, by which we can feed on God. We cannot feed on Him like the angels do, since we do not see Him with spiritual eyes like they do. We need a bodily way to feed on the Body, Blood, soul, and divinity of the Christ. That way is: the Holy Mass.