The Only Diet for a Peacemaker is Vegetarian
Sometimes in my Peace Studies class, students embrace pacifism as a kind of political philosophy, but they reject it as a personal belief system. That is, they think pacifism should be the norm for nations and that there should be no war, but they think that physical violence is sometimes necessary on a personal level. Namely, they want to reserve the right to protect themselves or loved ones in self defense. Some people argue that this is contradictory--if pacifism is an ethical doctrine, then it must apply universally to all people and situations in which aggression presents itself. See this for arguments about possible contradictions in pacifism.
John Dear presents another perplexing issue. He maintains that to be an authentic and effective peacemaker, someone dedicated to the activism of nonviolence, requires a vegetarian diet.
The production, processing, and consumption of animal protein is environmentally unsustainable and unhealthy, Dear says, and he presents various images of peace and nonviolence from Biblical sources to suggest that vegetarianism is a world view best suited to bringing peace to the world.
Is it contradictory to be a nonviolent activist and be a meat-eater?
Here is a video of Cesar Chavez suggesting that it might be: