On the sixth day, God gave humans green plants as food:
And God said, "Behold, I have given you every plant yielding seed that is on the face of all the earth, and every tree with seed in its fruit. You shall have them for food..." (Gen 1:29 ESV)
Then after the flood, meat was added to the diet:
Every moving thing that lives shall be food for you. And as I gave you the green plants, I give you everything. (Gen 9:3 ESV)
However, the NLT suggests that meat was already approved before the flood:
Take with you seven pairs--male and female--of each animal I have approved for eating and for sacrifice, and take one pair of each of the others. (Gen 7:2 NLT)
Several other translations render "each animal I have approved for eating and for sacrifice" merely as "clean animal" (Gen 7:2 parallel).
Is this a mistake in the NLT or could "clean animal" be correctly translated as "approved for eating" even before the flood?
Also, if the world was so corrupt that God decided to destroy it as described in Gen 6, could this mean that the human race already ate meat in violation of the prescribed diet before the flood? Furthermore, livestock is mentioned in Gen 4:20, but whether the meat was eaten is unclear.