5 September 2011
Switch hands for a healthier diet
by Kate Melville
Psychologists from the University of Southern California found that popcorn munching moviegoers ate about the same amount of popcorn regardless of whether it was fresh or one-week old, showing that bad eating habits persist even when the food we're eating tastes bad.
"For those in the habit of having popcorn at the movies, it made no difference whether the popcorn tasted good or not. When we've repeatedly eaten a particular food in a particular environment, our brain comes to associate the food with that environment and make us keep eating as long as those environmental cues are present," said study author David Neal.
The study, in the journal Personality and Social Psychology Bulletin, has important implications for understanding overeating and the conditions that may cause people to eat even when they are not hungry or do not like the food.
"People believe their eating behavior is largely activated by how food tastes. Nobody likes cold, spongy, week-old popcorn," said co-researcher Wendy Wood. "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 also gave popcorn to a control group watching movie clips in a meeting room, rather than in a movie theater. In the meeting room, a space not usually associated with popcorn, it mattered a lot if the popcorn tasted good. Outside of the movie theater context, even habitual movie popcorn eaters ate much less stale popcorn than fresh popcorn, demonstrating the extent to which environmental cues can trigger automatic eating behavior.
"The results show just how powerful our environment can be in triggering unhealthy behavior," Neal said. "Sometimes willpower and good intentions are not enough, and we need to trick our brains by controlling the environment instead."
In an interesting variant of the experiment, the same researchers asked participants about to enter a film screening to eat either stale or fresh popcorn with either their dominant or non-dominant hand.
Using the non-dominant hand seemed to disrupt established eating habits and caused people to pay attention to what they were eating. When using the non-dominant hand, moviegoers ate much less of the stale than the fresh popcorn, and this worked even for those with strong eating habits.
"It's not always feasible for dieters to avoid or alter the environments in which they typically overeat," Wood concluded. "More feasible, perhaps, is for dieters top actively disrupt the established patterns of how they eat through simple techniques, such as switching the hand they use to eat."