Imagine what the beans do to Hulk’s digestion.

On a serious note, the Hulk usually doesn't require food. In the old days he would eat as Banner and smash as Hulk. Only in situations where he was the Hulk for an extended period of time did he eat and it wasn't out of an actual need, but merely because he felt hungry. My thinking is that the Hulk's digestive system would be so efficient, he probably didn't... um... have to go to the bathroom, even if he ate solid food.

Steve Ditko's Hulk loved meat sticks.