In Leviticus 11 and Deuteronomy 14 God states the principles that are to be used to determine which animals would be beneficial to man's diet (called 'clean' animals and seafood) and which would not (designated as 'unclean'). Clean meats allowed in the Bible have a divided hoof and chew cud (Leviticus 11:3).
Animals that fulfill the requirements to be considered clean, and therefore includable in our diet, are cattle, deer, goats and sheep to name a few. Birds such as chickens, ducks, pheasants, turkeys and more can be consumed. The only insects that are permitted in the Bible for food are those of the Locust family. Animals that are BAD for man's health and therefore should be avoided entirely in his diet include pigs, horses, rabbits, squirrels, cats, and others.
Fish and other seafood that, according to Scripture, are fit for eating have fins and scales (Leviticus 11:9). God's designation means that fish like Tuna, Bass, Salmon, Cod, Herrings, Red Snapper, Smelt, and a whole bunch others can be safely enjoyed by humans. Popular seafood that should NOT be in our diet includes shrimp, lobster, catfish, squid, crabs, oysters, and others.
A common scripture used to support the notion that Jesus abolished his Father's laws concerning clean and unclean foods is found in Mark 7. Many people take these verses to mean that eating unclean things like shrimp, pork, lobster, etc. are acceptable because Christ says they do not harm us.
Don't you perceive that anything that enters into a man from outside is not able to defile him? 19. For it does not enter into his heart, but into the belly, and then passes out into the sewer, purging all food (Mark 7:18 - 19).
Is Jesus talking about the laws concerning diet found in Leviticus 11 and Deuteronomy 14? We find our answer in the parallel account of this event in Matthew 15. Jesus and his disciples are criticized regarding the CEREMONIAL washing of hands. This practice is not of God, nor does the Bible command it. It is strictly a tradition of men that religious leaders falsely elevated to the status of being MORE IMPORTANT than the commandments and judgments of God (Matthew 15:10 - 11). Christ was not teaching, in Mark 7, that God's laws regarding diet were suddenly null and void. He was discussing how human traditions can take the place of truly obeying the words of God. The physical, ritualistic traditions of men are nowhere near as important as a person's character.
Another well-worn argument regarding the diet God approves of revolves around the vision the Eternal gave to Peter in Acts 10. In the vision Peter sees a sheet full of many animals whose flesh was "unclean" to eat (Acts 10:11 - 12). He is three times offered the opportunity to kill and eat the animals on the sheet. His response is, "In no way, Lord; for I have never eaten anything that is common or unclean" (verse 14).
God's response was that what He cleansed Peter ought not to call 'common.' Does this somehow entail a new ruling by God that what HE HIMSELF had designated as a proper diet for his creation was no longer valid and could be ignored? Was this rare vision given for the sole purpose of allowing church fellowships to have shrimp, pork and catfish at their potlucks? Such an interpretation would be ridiculous to Peter. He tells us, while talking to the first Gentile convert to Christianity, that the real meaning of vision had nothing to do with diet (Acts 10:28)!
In short, Peter's vision had NOTHING to do with changing God's commands regarding diet or with annulling ANYTHING in his law. The vision was not God's way of communicating a change in his will, rather, it was meant to change the biased and bigoted view of Peter regarding non-Jews!
What did Paul teach?
16. Therefore, do not allow anyone to judge you in eating or in drinking, or with regard to a festival, or new moon, or the Sabbaths (Colossians 2:16)
Much of Christianity will tell you that the laws concerning diet, God's annual Feast Days, etc. were done away after the death of Christ. The Bible does not teach this. A review of church history shows that false teachings concerning the law, the change of Sabbath to Sunday, the change from Passover to Easter, and others were brought into the Church during the period from about 100 to 300 A.D.
The majority of believers in Colossae were, prior to their conversion, Gentiles and not Jews. They had not grown up learning about the law of God or trying to put in practice God's commandments like someone with a Jewish background. In their lives, they had eaten all kinds of unclean animals like pork in their diet. Paul was actually teaching the church to observe the laws of clean and unclean foods, to keep the Sabbath and so on!
There is absolutely no Biblical basis for teaching that God's laws of clean and unclean have been abolished and therefore can be ignored in the diet of a Christian. The distinction between what is clean and unclean will still be extant in the End Time when God judges Babylon (Revelation 18:2).