Mankind, from Adam to Noah, ate nothing but "fruits and veggies" (Gen. 3:17-19 through Gen. 6:24). It was not until after the Ark landed, that God changed the rules; He put fear of man in the "hearts" of all living things, and they were "added to the menu" (Gen. 9:2-4).
It was not until God gave the Law to the descendants of Abraham through Moses, that the "rules" changed. While the rest of the human race could continue eating any thing they chose, Abraham's people, Israel, were required to restrict their diet to things which are called "kosher" today. These dietary restrictions are mainly listed in Leviticus 11:1-47 and Deuteronomy 14:3-21. In addition, during some of Israel's Feasts, they were not permitted to eat anything that contained leaven. God even instructed the Jews to purge their homes of leaven so that there would not be a possibility that what they consumed might have been contaminated by it (Ex. 12:15-20). To this day, these dietary laws are binding upon all Jews.
Following the Resurrection of Jesus, His Ascension, and the birth of the Church at Pentecost, it took some time before Christians understood that they were no longer under the Law. In Acts 10:9-48, God used a vision to show Peter that, not only had the dietary rules changed for the Church, but that it would be made up of both Jews and Gentiles who accepted Christ as their Lord. Change came slowly among the Jewish members of the Church, but eventually, through the preaching and writings of Paul, they learned that the Church is not bound by the Law of Israel (Acts 15:5-30).
Today, born again believers can eat anything they choose, with one exception: we ought not to eat any food or drink any drink that offends a brother or a sister in Christ! In Romans 14:1-23, Paul tells us how we are to behave around brethren who have yet to come to an understanding of the difference between the Law of Israel, and the Law of Love (Mt. 7:12; Rom. 13:8-10; Gal. 5:13-14; Jam. 2:8)!
"Love worketh no ill to his neighbour: therefore Love is the fulfilling of the Law."