The food laws are part of an old dead covenant that was ended when Jesus died. You can't go back and just keep some of that law and think that it does you any good.
Galatians 5
"2 Indeed I, Paul, say to you that if you become circumcised, Christ will profit you nothing. 3 And I testify again to every man who becomes circumcised that he is a debtor to keep the whole law
You can't just pick and chose, if you pick one, you pick them all including animal sacrifice to atone for sins.
That law was nailed to the cross. We're not under that law anymore. We're under obligation to keep the law of Christ (see James). And in some cases, the restrictions are even stricter. For instance, under the old law, murder was the taking of a life. Under Christ's law, murder is hating your brother.
But the dietary laws and circumcision and the rest of it are done away with and the old law has been replaced. You can't go back and be justified by that law anymore.
While we are under the New Covenant and not the Mosaic Covenant, we are nevertheless still under the same God with the same nature and therefore the same instructions for how to walk in the same ways and express the same character traits. For example, the way to act in accordance with God's righteousness is straightforwardly based on God's righteousness, not on any particular covenant, and God's righteousness is eternal, so any instructions that God has ever given for how to act in accordance with His righteousness are eternally valid regardless of which covenant we are under, and the same goes for God's other character traits.
For example, in 1 Peter 1:16, we are told to have a holy conduct for God is holy, which is a quote from Leviticus where God was giving instructions for how to have a holy conduct, which includes refraining from eating unclean animals (Leviticus 11:44-45), so following those instructions is about testifying to the nations about God's holiness. Instructions for how to act in accordance with God's holiness can't be done away with without first doing away with God's holiness.
The Israelites needed to be taught about who God is and how to walk in His ways, so God's law was given for our own good for that purpose (Deuteronomy 10:12-13). God us trustworthy, so He law therefore is also trustworthy (Psalms 19:7, Nehemiah 9:13), and a law that isn't trustworthy can't come from a God who is trustworthy, so if we believe that God can be trusted to guide us in how to rightly live through His law and that it was given for His people's own good in order to bless us, then isn't a positive thing to seek by faith to learn how to walk in His ways according to the wholeness of His law? David said repeatedly through out the Psalms that he loved God's law and delighted in obeying it, so if we consider the Psalms to be Scripture, then we should consider him to be expressing a correct view of God's law, and should therefore share it.
So why would you think that it makes sense to interpret Galatians 5:2 was Paul warning us against doing that as though obedience to God were somehow a negative thing? All throughout the Bible, God wanted His people to repent and to return to obedience to His law, and even Christ began his ministry with that message, so it would make no sense whatsoever to interpret Galatians 5:4 as Paul warning us against doing that and saying that we will be cut off from Christ if we follow Christ. Paul was not an enemy of God, so his problem in Galatians was not with God's law, but with people teaching that Gentiles had to obey their works of the law in order to become justified.
There were no laws nailed to the cross. In regard to Colossians 2:14, whenever someone was crucified, the people would write out a sign that listed the charges that were against them and nail it to their cross in order to announce why they were being executed (Matthew 27:37). This served as a perfect analogy for the list of our violations of God's law being nailed to the cross and with him dying in our place to pay the penalty for our sins, but has nothing to do with ending any of God's laws, especially because they are all eternal (Psalms 119:160).
God is not in disagreement with Himself about which laws we should follow, so the Law of Christ is the same as the Law of the Spirit and the Law of the Father, which was given to Moses. Christ set a sinless example for how to follow how how to walk in obedience to the Mosaic Law and did not hypocritically preach something other than what he practices, so it wouldn't make any sense to think that the Law of Christ was something other than what he taught by word and by example. In Leviticus 19:17, we are instructed not to hate our brother in our hearts, so that was nothing brand new in violation of Deuteronomy 4:2. We aren't justified by obeying God's law because it was never given for that purpose in the first place.
