Mara is a vegan, partially for health reasons, and partially for her passion for the protection of animals. She's a face for the Humane Society of the United States, appearing in one of their promotional advert campaigns for 'Meatless Monday'. But giving up meat wasn't the hardest part for Mara as she explained to ContactMusic: "I'm a vegan, but that doesn't mean I get up and leave if I'm out to dinner with someone who orders steak. "Their biggest surprise is that I don't eat cheese anymore, and I don't blame them because cheese was definitely the hardest thing to give up."