Is John 6 proof of the real body and blood of Christ in the Eucharist?

My first video about the Bible and theology. This is a careful study of John 6, focusing on the question whether certain verses in John 6 constitute "proof texts" for the doctrine of transubstantiation, i.e., that the real body and blood of Christ are found in the Eucharist (Communion, Lord's Supper). I maintain that, so far from being proof texts, when put in their proper context, the strange and cryptic statements Jesus makes in the chapter have a purpose directly contrary to the doctrine. Catholic, Orthodox, and Lutheran believers need to take full account of the statement that "the spirit that quickeneth; the flesh profiteth nothing" (v63). In context, what does this say about "the body and blood of the Lord"?