Are you a mindless eater?

A new study reveals that people eat out of habit -- even when the food tastes bad.

Researchers at the University of Southern California had people watch movie trailers and gave them either freshly popped popcorn, or popcorn that was a week old.

Study participants who said they often noshed on popcorn at movie theaters ate the same amount-- regardless of whether it was fresh or cold and stale. Taste didn't matter.

When participants were given the popcorn in a different setting -- a conference room -- they ate considerably less stale popcorn.

The study was published in the journal Personality and Social Psychology Bulletin.