Do you remember that time strawberry ice cream made you sick?

Here’s a dieting technique you may not have come across before. Psychologists at the University of Washington misled people into believing they had been made ill by strawberry ice cream as a child, thus leaving them less willing to eat strawberry ice cream now.

Daniel Bernstein and colleagues gave hundreds of undergrad students six questionnaires to fill in about their food preferences, lifetime food experiences and their eating behaviour at parties. A week later the students were given false feedback – purportedly from a computer programme which had an analysed their earlier answers – informing them that as a child they’d “disliked spinach, enjoyed eating pizza and felt happy when a class mate brought sweets to school”. Some of the students were also told they had been “made sick after eating strawberry ice cream”. When the students then filled in some of the eating behaviour questionnaires for a second time, those who’d been given the false feedback about ice cream reported less preference for, and less willingness to eat strawberry ice cream than they had in the previous week’s questionnaires. In contrast, control students not given the false ice cream feedback didn’t show any change in their attitudes to ice cream. The aversive effects were stronger in a second experiment when the students given false feedback were also asked to reflect on their (fictitious) bad experience with ice cream.

However, the false feedback technique didn’t work for chocolate chip cookies, a fact the authors speculated might be because the students expressed a stronger initial preference for cookies, and reported eating them more regularly.

“…our findings have important implications for food choices and dieting…”

“We believe that our findings have important implications for food choices and dieting”, the authors concluded. “If people can be led to avoid certain fattening foods simply by believing that they had a negative experience with those foods as children, then perhaps people could learn healthier eating habits”.

Bernstein, D.M., Laney, C., Morris, E.K. & Loftus, E.F. (2005). False beliefs about fattening foods can have healthy consequences. Proceedings of the National Academy of Sciences, USA, Early Edition.

Post written by Christian Jarrett (@psych_writer) for the BPS Research Digest.