Eating habits can cause people to continue consuming junk food even when it stops taste good – like stale popcorn at the movies – according to a new study published in the Personality and Social Psychology Bulletin.
Researchers from the University of Southern California devised an experiment where they randomly gave moviegoers either fresh or week-old popcorn. Of those who didn’t normally eat popcorn at the movies, stale popcorn meant lower consumption. For those who always ate popcorn at the movies, however, the freshness didn’t matter: they ate the same amount regardless.
"People believe their eating behavior is largely activated by how food tastes. Nobody likes cold, spongy, week-old popcorn," explained Wendy Wood, one of the study authors.
"But once we’ve formed an eating habit, we no longer care whether the food tastes good. We’ll eat exactly the same amount, whether it’s fresh or stale."
The researchers repeated the experiment, but this time showed a movie in an office boardroom. Taken out of the familiar setting of a movie theater, even popcorn lovers declined to eat much of the stale popcorn. Even back within the movie theater setting, they were more likely to notice the staleness if they were made to eat with their non-dominant hand.
"It’s not always feasible for dieters to avoid or alter the environments in which they typically overeat," Wood said.
"More feasible, perhaps, is for dieters to actively disrupt the established patterns of how they eat through simple techniques, such as switching the hand they use to eat."