Memory manipulation may lessen appeal of certain unhealthy treats

Most dieters know that the mind is a powerful force in the battle of the bulge; but a new study led by psychologist Elizabeth Loftus shows that the malleable nature of human memory might be used to help people avoid certain fattening foods.

In the first study to show false memories have potential to curb appetites for fattening treats, Loftus' research team found that people can be led to believe they got sick as children from a specific food such as strawberry ice cream. As a result, they were less inclined to eat strawberry ice cream as adults. Loftus, whose research over three decades has changed the way scientists and the public view aspects of human memory, recently conducted several studies showing that false memories can influence future behavior, including decisions as fundamental as food choice.

The findings are presented this week in the online version of the Proceedings of the National Academy of Science.

"We believe this new finding may have significant implications for dieting," said Loftus, a distinguished professor at UC Irvine. "While we know food preferences developed in childhood continue into adulthood, this work suggests that the mere belief one had a negative experience could be sufficient to influence food choices as an adult."

After 204 students completed questionnaires about their food preferences, they received computer-generated analyses – some of which included false feedback indicating they had gotten sick from eating strawberry ice cream as a child. Researchers used two techniques to encourage the participants to process the false information, which resulted in 22 percent and 41 percent of the participants believing they had such a childhood experience. Participants even provided details of the experience such as "May have gotten sick after eating seven cups of ice cream." However, both groups showed similar tendency to want to avoid that food now that they "remembered" getting sick from it as a child.

"People do develop aversions to foods; for example, something novel like béarnaise sauce may make someone sick once, and they can develop a real aversion to that food," said Loftus. "And with alcohol, there's a medication that actually makes alcoholics sick if they drink, and the idea is to develop an aversion so that the person avoids drinking. It may be possible to do something similar with food, but without the physical experience."

Loftus points out that further research must be done to show whether the effects are lasting and whether people who believe the false memory actually avoid the food when it is in front of them, as they indicated in the surveys.

In experimenting with false memories about fattening foods, Loftus' team looked at both chocolate chip cookies and strawberry ice cream. Because participants were more likely to believe strawberry ice cream had made them ill, the researchers speculate that only novel food items are effective with the false feedback technique – a finding consistent with research showing real taste aversions are more likely to develop with novel foods. How recently participants had eaten the food appeared to have no effect.

In next study, Loftus and her team will look at whether people can be led to falsely believe that as a child they really liked certain healthful vegetables, like asparagus, and whether that will make them more inclined to eat such foods as adults.

Study co-authors include Daniel M. Bernstein of the University of Washington and Kwantlen University College, as well as Cara Laney and Erin K. Morris of UCI.