Genesis 8:20 -- clean/unclean animals is with reference to sacrifice
Genesis 9:3 "just as I gave you the green plants, I now give you everything"
Genesis 1:29 in re: green plants "they will be yours for food"
definitely concerning diet in both places. if i accept your view i have to see Adam as a pure carnivore before being given *also* plants to eat? and His words to Noah as 100% superfluous and without meaning.
know of any actual scripture that says 'unclean' = 'not good for physical health' ?
keeping in mind the consistency of God why does He explicitly command Peter to eat 'unclean' animals?
do you know of any other scripture where God gives a vision to someone literally commanding them to do evil ((as you suggest Acts 10 is)) purely as a metaphor for doing something good? the position that God commands Peter three times to commit sin is inconsistent. the position that what is true about men of all nations being now accepted by God through faith, is also true about all foods He has created being acceptable in His sight when received in faith, is consistent.
Peter does not mention his vision to Cornelius and those gathered - not as recorded in scripture.
to convince me, you need to find me an example of God explicitly commanding someone to do what is wicked in His sight, being purposefully deceptive. your position has God more than tempting Peter, in fact compelling him to do evil, and i find it entirely unsupportable. God is consistent: He doesn't tell you to do exactly the opposite of what He secretly desires for you to do. He does not instruct you to sin and He does not lie.