The Gnostics were vegetarians, as were the Essenes, the Jesus Movement, Manichaeans, Cathars, and the Church of the Light based in China: https://www.youtube.com/watch?v=6kJh66vIJz0&ab_channel=AeonByteGnosticRadio
Evidence That Jesus and The Original Aramaic Christians Were Vegetarians: “James was a vegetarian….” (Robert Eisenman, James the Brother of Jesus) “James, the brother of the Lord, lived on seeds and plants and touched neither meat nor wine.” (Epistulae ad Faustum XXII, 3) “John never ate meat.” (Church historian Hegesipp according to Eusebius, History of the Church II 2:3) “The Apostle Matthew partook of seeds, and nuts, hard-shelled fruits, and vegetables, without flesh.” (Clement of Alexandria, The Instructor, Book 2, Chapter 1) Peter said, “I live on olives and bread, to which I rarely only add vegetables.” (Clementine Homilies 12,6; also see, Recognitions 7,6): https://medium.com/sant-mat-meditation-and-spirituality/b8784ac42506
Uncovering A Vegetarian Jesus at the Beginning of Christianity: "Now beware in yourselves that your hearts do not become heavy with the eating of flesh and with the intoxication of wine and with the anxiety of the world, and that day come up upon you suddenly; for as a snare it will come upon all them that dwell on the surface of the earth.” (Jesus, Luke 21:34, from a Syriac-Aramaic manuscript of the New Testament): https://medium.com/sant-mat-meditation-and-spirituality/9279741be7c4