Do you often eat more than you should? Join the club. Many of us mindlessly munch out of habit or occasion (e.g., movies, parties). Even the repetitive motion of hand-to-mouth can take on a momentum all its own. Researchers at USC wanted to see if they could break up such unconscious eating behaviors by changing things up on study subjects who were habitual popcorn eaters -- simply by getting them to switch the hand with which they scoop their snack.