Eating and drinking are significant in that if you are unable to do either of them you will die. As such they are symbols for the sustenance of life. And life itself is symbolic of our spiritual condition, our relationship or communion with God.
Genesis 2:16-17 ESV 16 And the Lord God commanded the man, saying, “You
may surely eat of every tree of the garden, 17 but of the tree of the
knowledge of good and evil you shall not eat, for in the day that you
eat of it you shall surely die.”
It is significant that it speaks of 'eating' of the fruit here too.
Jesus spoke a lot about this, because that was why He came. He was both of those for us:
Matthew 5:6 ESV “Blessed are those who hunger and thirst for
righteousness, for they shall be satisfied."
John 6:53 ESV So Jesus said to them, “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.
This concept is so foundational and incredibly important that Jesus talked about it just before He was crucified and even commanded us to remember it through the partaking of communion.
Now, whilst eating and drinking are very similar, they are still different. "Eating" is representative of the physical, and "Drinking" is representative of the spiritual. For Example:
John 4:34 ESV Jesus said to them, “My food is to do the will of him who
sent me and to accomplish his work.
John 4:13-15 ESV 13 Jesus said to her, “Everyone who drinks of this water
will be thirsty again, 14 but whoever drinks of the water that I will
give him will never be thirsty again. The water that I will give him
will become in him a spring of water welling up to eternal life.”
Now this is really significant when it comes to communion. Jesus is the "Bread of Life" and is full of the Holy Spirit.
His body was physically broken at the whipping post and Isaiah 53/Matthew 8/1 Peter 2 state that this was to redeem our physical condition. "By His stripes we are/were healed". As we eat the bread, we recognise that we are physically connected to God in that we are physically here to do the works of Jesus here on Earth and that we have the benefits of divine health also. A two way relationship. (Look at 1 Cor 11:29-30) Have you ever wondered why Jesus chose to die in such a painful horrible way if it was just his death that mattered?
His blood was poured out for us on the cross. He died (physically) that we might have life (spiritually). As we drink the wine, we recognise that we are spiritually connected to God in that because of what Jesus did, we can stand before Him holy and righteous (Colossians 1:22). We are given everlasting life. We are given the Helper, the Holy Spirit of God.
Given the significance of this topic, I feel I have done it no justice at all. In the same way that the body and the blood are interrelated, the physical and the spiritual are interrelated - eating and drinking are interrelated. As such it is difficult to distinguish between them. However the more you search the scriptures, the more you will see this pattern emerge!