In the New Testament the Lord’s Supper was often called the breaking of bread. Three of the gospels record when Jesus instituted it: Matthew 26:26-28, Mark 14:22-24 & Luke 22:19-20.
And as they were eating Jesus took bread, blessed it and broke it, and gave it to the disciples and said. “Take eat this is my body.” Then He took the cup and gave thanks and gave it to them saying. “Drink from it all of you.” [Matt26:26-28]
We can note that when Jesus said "Take eat this is my body" his actual body was physically there and he was not offering his disciples his actual flesh. So the bread was symbolic of something much deeper. When we are baptised into Him, His death and resurrection becomes ours and as we feed on Him we die to our old life style and rise in Him into a new life style.
The risen Jesus revealed to Paul this practice. That it was an act of remembrance of what He had done for us and that He is now the source of our inner life.
For I received from the Lord that which I also delivered to you, that the Lord Jesus on the same night in which He was betrayed took bread, and when He had given thanks He broke it and said, “Take, eat, this is my body which is broken for you. Do this in remembrance of Me.” In the same manner He also took the cup after supper saying, “This cup is the new covenant in My blood. This do, as often as you drink it, in remembrance of Me.” For as often as you eat this bread and drink this cup you proclaim the Lord’s death till He comes. [1 Cor11:23-26]
The bread and wine are symbols of the spiritual reality.
I am the bread of life. Your Fathers ate the manna in the wilderness and are dead. This is the bread which comes down from heaven, that one may eat of it and not die. I am the living bread which came down from heaven. If anyone eats of this bread He will live forever, and the bread that I shall give is My flesh, which I shall give for the life of the world. … Most assuredly I say to you unless you eat the flesh of the Son of Man and drink His blood you have no life in you. Whoever eats my flesh and drinks my blood has eternal life and I will raise him up at the last day. For My flesh is food indeed and My blood is drink indeed. He who eats My flesh and drinks My blood abides in Me and I in Him. As the living Father sent Me and I live because of the Father so he who feeds on Me will live because of Me. This is the bread which came down from heaven, not as your fathers ate the manna and are dead. He who eats this bread will live forever. [John 6:47-51 & 53-58]