According to the results of a study released in August, it is possible to convince people that they don’t like certain fattening foods – by giving them false memories of experiences in which those foods made them sick.
The research was conducted by a team including Elizabeth Loftus, a psychologist at the University of California, Irvine, who is known for her previous work showing the malleability of human memory and calling into question the reliability of recovered memories in sexual-abuse cases. She turned her attention to food as a way to see if implanted memories could influence actual behavior.
After initial experiments, in which subjects were persuaded that they became ill after eating hard-boiled eggs and dill pickles as children, the researchers moved on to greater challenges. In the next study, up to 40 percent of participants came to believe a similarly false suggestion about strawberry ice cream – and claimed that they were now less inclined to eat it.
The process of implanting false memories is relatively simple. In essence, according to the paper that Loftus’s team published in Proceedings of the National Academy of Sciences, subjects are plied with "misinformation" about their food histories. But a number of obstacles remain before members of the general population can use this technique to stay thin. Attempts to implant bad memories about potato chips and chocolate-chip cookies, for instance, failed. "When you have so many recent, frequent and positive experiences with a food," Loftus explains, "one negative thought is not enough to overcome them."
More work is needed to determine if the false-memory effect is lasting and if it is strong enough to withstand the presence of an actual bowl of ice cream. It’s also not clear, at this point, how people could choose to undergo the process without thereby becoming less vulnerable to this kind of suggestion.
Nevertheless, the technique does seem to work. Loftus’s newest, unpublished studies have looked at whether a memory of a positive experience with a healthy food could be implanted. And indeed, she says, "we can convince people they really loved asparagus the first time they tried it as a kid."