Manipulating our memories of food can influence what we choose to eat

Using food, UCI psychologist Elizabeth Loftus demonstrates false beliefs can affect people’s later thoughts and behaviors

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.”

Loftus’ colleagues in the food studies are Daniel Bernstein of the University of Washington and Cara Laney and Erin Morris of UCI.

Q & A with Elizabeth Loftus:

Q. Why did you choose to experiment with food?

We were looking for a way to assess whether false memories have consequences for people, affecting their later thoughts and behaviors, and food seemed a reasonable way to do that. We ended up picking hard-boiled eggs and pickles because we needed items that would likely be in someone’s past, but wouldn’t be too common.

Q. What findings surprised you?

The implications for dieting hadn’t occurred to me until I started seeing the results. The people who believed the false feedback not only showed avoidance for the critical food item (i.e. hard-boiled egg), but also for a closely related item such as egg salad. Now, the idea that you can tap into people’s imagination and mental thoughts to influence their food choices sounds exciting. At the same time for a health professional, it’s difficult, as it’s unethical to lie to patients.

Q. Are there limits on the kind of foods you can do this with? Can you turn people off to fattening foods?

The process seems to work best when the food item is somewhat novel. Planting false memories of getting sick on strawberry ice cream led to food avoidance, but avoidance did not occur for potato chips.

Q. What are the implications of this finding in relation to your other research?

This is a continuation of my research on the malleability of memory. As we learn more about the link between a false belief and consequences, we may be able to understand what happens in the real world. This is basic science about memory distortion, we have yet to explore the possible applications.

Q. How can people recognize when a false memory has been implanted?

As far as we know, people can’t determine when they’ve had a false memory implanted. In our research, we debrief after each experiment, so participants know what happened.