Jesus is the bread which came down from heaven. We see in John chapter 6 that fragments of bread are symbolic of believers in Christ. We read, "When they were filled, he said unto his disciples, Gather up the fragments that remain, that nothing be lost. " Here, we find the same terminology used for believers used for bread - gathering those that remain that none be lost. Interestingly, the bread is placed in 12 baskets. 12 is the number of tribes of Israel, for example (who are a picture of all believers).
John the Baptist ate locusts and wild honey. This was symbolic of how he ingested the word of God - a picture of how the word is a two edged sword, being judgment and mercy.
Satan eats human beings. We find this out in Genesis 2: "dust shalt thou eat all the days of thy life ". Yet the Bible calls people dust in the next chapter: " for dust thou art ". This should be taken as meaning that Satan consumes or fellowships with humans spiritually.
The believers eat human beings as well, but also only in a spiritual sense also. First of all, we eat the body of Christ and drink his blood: "Whoso eateth my flesh, and drinketh my blood, hath eternal life; and I will raise him up at the last day. " This does not mean that we have a big physical glass full of real blood for breakfast. Rather, we ingest what Christ has done for us by believing on his sacrifice and atonement. The disciples ate people in the spiritual sense: "his disciples began, as they went, to pluck the ears of corn " and this was on the Sabbath day. Yet the Bible shows us that grain is a picture of believers since one who shares the word is like an ox treading out grain.