Research explains why people eat junk food mindlessly: Environmental cue signals

Posted by AFN Staff Writers on 8th September 2011

A research paper published today by University of Southern California (USC) claims to explain why many people with bad eating habits continue to eat unhealthy foods – even when the food doesn’t taste good.

The researchers gave people about to enter a cinema a bucket of either just-popped, fresh popcorn or stale, week-old popcorn.

Those who didn’t usually eat popcorn at the cinema ate much less stale popcorn than fresh popcorn. But those who indicated that they typically had popcorn at the cinema ate about the same amount of popcorn whether it was fresh or stale.

Professor of Psychology and Business at USC Wendy Wood said, “For those in the habit of having popcorn at the movies, it made no difference whether the popcorn tasted good or not.

“People believe their eating behavior is largely activated by how food tastes. Nobody likes cold, spongy, week-old popcorn. 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 is fresh or stale.”

The study, in the current issue of 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.

Lead author of the research paper David Neal was a psychology professor at USC when the research was conducted and now heads a social and consumer research firm. He said, “When we’ve repeatedly eaten a particular food in a particular environment, our brain associates the food with that environment and we keep eating as long as those environmental cues are present.”

The researchers controlled for hunger and whether the participants liked the popcorn they received. The researchers also gave popcorn to a control group watching movie clips in a meeting room, rather than in a cinema.

Mr Neal said, “In the meeting room, a space not usually associated with popcorn, it mattered a lot if the popcorn tasted good. Outside of the cinema 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.”

A simple solution for bad eating habits: Switch hands!

In another cinema-based experiment, the researchers tested a simple disruption of automatic eating habits. Once again using stale and fresh popcorn, the researchers asked participants about to enter a film screening to eat popcorn either with their dominant or non-dominant hand.

Ms Wood said, “Using the non-dominant hand seemed to disrupt eating habits and cause people to pay attention to what they were eating. When using the non-dominant hand, movie-goers 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. More feasible, 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.”