I would rephrase that as "whole world was suppose to be vegetarian prior to the biblical universal flood."
Man is doing what ever it wants inside and outside the church like in the time of Noah.
I do stand corrected. When we recall that “GOD saw that the wickedness of man was great in the earth, and that every imagination of the thoughts of his heart was only evil continually”, it seems that some were eating meat as well as all the others evil deeds.