Jesus calls Himself the Bread of Life, so what does that mean and are there any Old Testament references about this?
The Great “I AM”
The Holy Name God gave Moses to tell the children of Israel in case they ask His Name was “I AM,” or “I Am the Self-Existent One.” Some translations have it “I AM that I AM” but they are all close to the same. God has been, and is now, and will always be, forever. The eternal God, Who some call, “Altogether different” or totally “other,” and that’s accurate. The word “holy” in Hebrew means “to separate or cut off,” so God is a cut above all of His creation and He is totally separate from His creation. How? He is not composed of matter as we and the universe is. He is Perfection, without sin, and Holy above all things. We are most certainly not (Rom 3:10-12, 23). So first of all, we must realize Jesus is God and whoever denies that, is an “anti-Christ,” or “against Christ,” as if you are not for Christ, He is against you (Matt 12:30). 
The Bread of Life
When God fed the ancient Israelites the manna from heaven, they ran out into the fields and said, “Manna,” which is literally, “What is it?” Today, it’s “Who is it?” and of course, it’s Jesus, that’s Who! He is the Bread of Life that came down from heaven to bring us eternal life. That’s why Jesus refers to Himself as the Bread of Life. In John 6:47-49 He says, “Truly, truly, I say to you, whoever believes has eternal life. I am the bread of life. Your fathers ate the manna in the wilderness, and they died.” First of all, Jesus uses the Old Covenant Name for God…saying “I Am” the bread of life. Now, compare that manna which the Jew’s fathers ate and died to the eternal life given through the Bread of Life. Why did the Israelites die? Because they didn’t obey God, but now, whoever believes in Jesus, even if they die, they will live again. He is the God of the living and not the dead. Our Lord said, “I am the resurrection and the life. Whoever believes in me, though he die, yet shall he live, and everyone who lives and believes in me shall never die. Do you believe this” (John 11:25-26)? I hope you do believe this. Otherwise, like the ancient Israelites, your physical bread will not be enough…and you will die…even worse, you will die in your sins.
I have always wondered if Jesus was referring to Communion or the Lord’s Supper, which had not yet been instituted in the New Covenant, but soon would be. The reason I say that is because Jesus said, “This is the bread that comes down from heaven, so that one may eat of it and not die. I am the living bread that came down from heaven. If anyone eats of this bread, he will live forever. And the bread that I will give for the life of the world is my flesh” (John 6:50-51). We see the bread taken at Communion as symbolic of Jesus’ own body given for us so that we might receive eternal life. Every time we partake of the Communion elements (the bread and the juice), we are reminded of Christ’s supreme sacrifice, but also it reminds us that He is coming again. The Apostle Paul wrote, “For as often as you eat this bread and drink the cup, you proclaim the Lord’s death until he comes” (1 Cor 11:26).
The Bread and Wine
On studying these passages, it’s almost as if Jesus is saying Communion is an integral part of the Body of Christ’s function because now Jesus mentions His own blood, and that we must drink it! Of course, the Bible commands us to not drink blood, so this must be symbolic of the Lord’s Supper and again, partaking of the bread and wine represent His body and blood. Jesus said, “Truly, truly, 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 feeds on my flesh and drinks my blood has eternal life, and I will raise him up on the last day. For my flesh is true food, and my blood is true drink. Whoever feeds on my flesh and drinks my blood abides in me, and I in him” (John 6:-53-56). Jesus main point is, “whoever feeds on me, he also will live because of me. This is the bread that came down from heaven, not like the bread the fathers ate, and died. Whoever feeds on this bread will live forever” (John 6:57-58). There is great spiritual significance in these elements, because we know we’re not literally eating His flesh and drinking His blood. That’s called “cannibalism,” and the Bible forbids it, so this is clearly a reference to the bread and the wine that we receive during Communion, so as Jesus said that “whoever feeds on me, he also will live because of me.”
Jesus and the Manna
Manna came down from heaven; Jesus came down from heaven
Manna is food from heaven; Jesus’ body is food (Communion)
Manna brought physical life; Jesus brought eternal life
Manna had oil; Jesus was full of the Holy Spirit
Manna was prepared; Jesus’ body was prepared of the Father (Heb 10:5)
Manna was pure white, with no corruption; Jesus was sinless and brighter than the sun (Acts 26:13); neither was sin found in Him
Manna was a gift; Jesus’ life was freely given for us and is unearned (Eph 2:8-9)
Manna was given to Jews, and a mix of aliens/strangers; Jesus saves both Jew & Gentile
Manna was delicious; Jesus’ life and death was a sweet, savory offering unto God (2 Cor 2:15)
Manna was a complete, balanced food; Jesus provides us with all we need
Manna is pounded, grounded, and put thru the fire; Jesus suffered the wrath of God for our sins (fire) and He was wounded for our transgressions & crushed for our inequities (Isaiah 53:5).
I hope you are a part of a local Body of Christ where you live. If not, you cannot partake of the Lord’s Supper in the way the Bible dictates, so “let us consider how to stir up one another to love and good works, not neglecting to meet together, as is the habit of some, but encouraging one another, and ball the more as you see the Day drawing near” (Heb 10:24-25). The “Day,” being the coming judgement of God which will come when no one expects it (Rev 1:7), “Therefore you also must be ready, for the Son of Man is coming at an hour you do not expect” (Matt 24:44). For many, it will be too late. If you’ve never trusted in Christ, only God’s wrath awaits you, so I pray, no…I plead with you today, make today your day of salvation (2 Cor 6:2). To wait, may make it too late…and that would be dreadful beyond description (Rev 20:12-15; Rev 21:8).
Here is some related reading for you: What Was Manna in the Bible? 
Resource – Scripture quotations are from The Holy Bible, English Standard Version® (ESV®), Crossway Bibles. (2007). ESV: Study Bible: English standard version. Wheaton, Ill: Crossway Bibles. Used by permission. All rights reserved.