I have never met so many vegetarians since coming to the UK. I'm more of Peteresque, "kill and eat" kind of a guy. If found interesting then, Barth's comments on Romans 14 about vegetarians:
"Contrasted with the strong man is the weak man who – eateth only vegetables. This, at any rate, is a clear, concrete standpoint. The uninstructed, non-Pauline man has this advantage at least. His ambiguity is not at once obvious; he does, at any rate, do something. Party-men, Sectarians, Churchmen, are vigorous and full of life. They occupy a position. They have pronounce characteristics. Their lives form a proper subject for the biographer. They are concerned with ‘deeds and facts’. Ranged behind the vegetable eaters at Rome we see the devotees of Orpheus and of Dionysus, the Neo-Pythagoreans, the Therapeutes, and the Essences, of the Ancient World; the Monks of the Middle Ages; the Baptists of the Age of the Reformation; the Total Abstainers, the Open-Air Enthusiasts and the Vegetarians of the Present Day."
This passage needs to be put in context of what Barth says about freedom, detachment, and the true Paulinist; however, Pagans and Baptists and Vegetarians are just different manifestations of the same problem.
