Anyone who's tried to change their eating habits knows that good intentions don't always translate into different choices. You might want to eat more vegetables or try new foods, but that doesn't mean your longtime favorites suddenly lose their appeal.
A new Yale University study suggests our existing food preferences may be part of the reason. Researchers found that people had more difficulty learning new information about foods when it conflicted with what they already liked. The findings, published in Communications Psychology, offer a glimpse into how familiar preferences may influence dietary change, although the experiment did not measure what participants actually ate.
The study involved 279 adults who first rated pictures of 65 snack foods according to how much they liked or disliked them. Researchers then selected four foods for each participant and used them in a computer-based exercise.
During the exercise, foods were paired with positive or negative points. Sometimes the pairings matched people's preferences, rewarding foods they liked and assigning negative points to foods they disliked. Other times, the pattern was reversed.
Participants had to figure out which foods were associated with which outcomes, even as the rules changed.
As expected, people generally had an easier time learning patterns that matched their existing preferences. But the researchers also discovered that their first experience mattered. When participants initially encountered patterns that reinforced their likes and dislikes, they had more difficulty adjusting when those patterns changed.
The difference was especially noticeable with favorite foods.
Participants struggled more to learn new associations that contradicted their positive feelings toward foods they already enjoyed. Foods they disliked, on the other hand, appeared more open to change.
In fact, participants who initially encountered patterns that challenged their preferences rated some previously disliked foods more favorably after the exercise. They reported slightly greater expected enjoyment and satisfaction and were willing to pay a little more for those foods.
The changes were small, and participants never actually tasted the foods. Still, the results raise an interesting question: Could learning to appreciate foods we don't particularly like be easier than trying to make our favorites less appealing?
The researchers also found that people learned positive associations more readily than negative ones. Participants correctly identified positive outcomes about 69% of the time, compared with 61% for negative outcomes.
That difference suggests a possible direction for future research into healthier eating habits. Rather than focusing primarily on why certain foods should be limited, researchers could explore whether emphasizing the appealing qualities of other foods helps people become more receptive to them.
But the study doesn't establish that positive messages change eating habits. Participants were predicting points associated with food pictures, not making actual food choices. Researchers also don't yet know whether the same learning patterns would appear outside an experimental setting.
This research was supported by the National Institutes of Health.