Vegan boxer Bryant Jennings will compete against undefeated Colombian fighter Oscar Rivas tonight for the title of World Heavyweight Champion. Jennings adopted a plant-based diet in 2015 to improve his health and mental clarity. “I was a vegetarian before that, but I became a vegan for health reasons, based on particular additives and ingredients in food,” Jennings told The Guardian. “I just thought healthy eating, clean eating was much better. And it really has been great for me.” Jennings typically consumes peanut butter and jelly sandwiches, whole grains, fruit and vegetables, and makes his own vegan burger patties from a combination of chickpeas, lentils, black beans, and quinoa. “I’m not fighting to prove anything,” Jennings said. “I’m just proud of who I am. When I have a great performance, I say, ‘See, I guess I don’t need meat.’ When I lift something that’s heavy that people say I couldn’t do, I say, ‘See, I guess I don’t need meat.” If Bryant wins tonight’s fight—which can be viewed on ESPN starting at 9:30 pm EST—he will become the world’s first vegan boxer to hold a heavyweight world champion title.