London: Ever wondered why you cannot resist eating popcorn at the movies, even if it`s stale? It`s because people do not keep eating junk food just because it is tasty, scientists say.
Instead, people develop a habit once they have associated a place with a certain kind of food, like popcorn at the cinema, the University of Southern California study found.
The researchers devised a test to see what causes us to overeat. They gave people about to enter a cinema a bucket of just-popped fresh popcorn, or stale week-old popcorn.
Moviegoers who did not usually eat popcorn at the movies ate much less stale popcorn than fresh popcorn because it just did not taste good.
But those who said they typically had popcorn at the movies ate about the same amount of popcorn whether it was fresh or stale, the Daily Mail reported.
In other words, for those in the habit of snacking at the movies, it made no difference whether the popcorn tasted good or not, the researchers said.
Co-author Wendy Wood said: "People believe their eating behaviour 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`s fresh or stale."
The findings, published in the journal Personality and Social Psychology Bulletin, have important implications for understanding overeating and the conditions that may cause people to eat even if they are not hungry or don`t like the food, the researchers said.
"When we`ve repeatedly eaten a particular food in a particular environment, our brain comes to associate the food with that environment and makes us keep eating as long as those environmental cues are present," said David Neal, who led the study.