The eating of human flesh and drinking human blood was anathema to the Jews, and Christ's teaching repulsed some of them, who had no glimmer of understanding of Christ.
If I'm not mistaken, the translation of one of verbs in the John gospel actually means "munch" more than it means "eat."
**I am the bread of life, he said (Jn 6: 35). I am the living bread that came down from heaven; whoever eats this bread will live forever; and the bread that I will give is my flesh for the life of the world (Jn 6: 51).**
"As the living Father sent me, and I live because of the Father, so he who eats me will live because of me" (John 6:57). The Greek word used for "eats" (trogon) is very blunt and has the sense of "chewing" or "gnawing."
We are one body with Jesus. Perhaps in the same sense that a baby and its mother are one. That is how the baby survives. Jesus helps us to survive in this life until we are reborn in the eternal life.