I had a roommate in college who's diet consisted of whole loaves of Grandma Sycamore bread and diet mountain dew. He would buy a loaf each day, and eat it dry. He'd wash it down with two or three mountain dews and then play Super Smash for the rest of the day. I didn't actually ever see him eat anything but bread and mountain dew.
Potatoes probably would have been a better option.