Changing memories of food may be a way to influence eating habits

Dec 13 2004

For the millions of Americans who worry about overeating during the holiday season, there may be hope: A new UC Irvine study suggests changing their memories of food may be a way to influence their eating habits.

With food as the subject, UCI psychologist Elizabeth Loftus conducted the first scientific demonstration of the effect of false beliefs on people’s subsequent thoughts and behaviors.

Loftus’ research team conducted two experiments using a series of questionnaires and false feedback to convince people that, as children, they had become sick after eating hard-boiled eggs or pickles. As a result, these people later indicated they would avoid these foods – proving that false memories can influence future behavior, even swaying fundamental decisions about what to eat.

“We set out to test what we’ve known anecdotally – that false beliefs have repercussions, affecting what people later think and do,” said Loftus, whose research over the past three decades has changed the way scientists and the public view the malleable nature of human memory. “We proved this; however, we also discovered that food is a surprisingly easy target for memory manipulation.”

The findings are to be published in the February issue of Social Cognition.

For the study, researchers asked 336 college student volunteers to fill out a food history questionnaire about their childhood eating experiences. A week later, they were presented with a computer-generated food profile that included the falsehood about getting sick after eating either a hard-boiled egg or a pickle. More than 25 percent confirmed that they “remembered” getting sick or “believed” that they did. Then in a questionnaire about party behavior, participants were asked how likely they would be to eat specific foods at an afternoon barbecue. Compared to a control group, the believers were more likely to avoid the pickles or hard-boiled eggs.

Still, Loftus explained, there may be limits to influencing eating habits. In another just-completed study using similar methods, Loftus convinced people they had become sick from eating potato chips as children. Although the participants “believed” the falsehood, they did not alter their behavior for this popular, hard-to-resist item. “Now we’re speculating that avoidance may only occur if the food item is novel,” Loftus said. “For instance, it worked with strawberry ice cream.”

On the other hand, the researchers tackled a healthy food by implanting a phony memory of a positive experience with asparagus. They found that people later showed increased inclination to eat the green spear-like vegetable.

“The idea that we can tap into people’s imagination and mental thoughts to influence their food choices sounds exciting, but it’s too preliminary to tell how this might be applied in the dieting realm,” cautions Loftus. “Our next step is to obtain grant funding to experiment with real food.”