According to the Best Week Ever, Jarod sold porno out of his dorm room and he was so into it that he had no time to eat. Well, thankfully a Subway opened at the bottom of his dorm building and he could run down to eat. So, Jarod did not start eating Subway because it was healthy, but because it was the closest option. If there was a McDonalds downstairs, he would have eaten that.
