US: In their battle against the bulge, desperate dieters have tried drugs, surgery, exercise, counselling, creams and even electrical fat-burning belts.
Now some psychologists have a new idea: lying.
A team led by psychologist Elizabeth Loftus of the University of California, Irvine, has found that it could persuade people to avoid fattening foods by implanting unpleasant childhood memories about the food - even though the event never happened.
In a paper published in yesterday's edition of the Proceedings of the National Academy of Sciences, the team said it had successfully turned people off strawberry ice cream and, in earlier studies, it has done the same with pickles and hard-boiled eggs - in each case, by manipulating the subjects to believe the foods made them sick when they were children.
The scientists say they have also successfully implanted positive opinions about asparagus by convincing subjects that they once loved the vegetable.
The method, if perfected, could induce people to eat less of what they shouldn't and more of what they should, Prof Loftus said. Good memories about fruits and vegetables could be implanted, and bad ones about low-nutrient, high-calorie foods.
In the strawberry ice cream experiment, Prof Loftus and her team asked 131 students to fill out forms about their food experiences and preferences, including questions about their experiences with strawberry ice cream. The subjects were then given a computer analysis of their responses that was supposed to indicate their "true" likes and dislikes.
A group of 47 students, however, were also inaccurately told that the analysis made it clear they had got sick from eating strawberry ice cream as a child. Of these, almost 20 per cent later agreed on a questionnaire that they had, in fact, been sickened by the treat and that they intended to avoid it in the future. The findings were stronger in a second experiment where - in addition to the other steps - students were asked to provide details about the imaginary strawberry ice cream episode. In that case, 41 per cent of the subjects given erroneous information later believed the tale and said they intended to avoid the food.
Several weight-control experts expressed interest in the study, but scepticism about using implanted memories as a dieting technique.
Michael Strober, professor of psychiatry and director of the eating disorders programme at UCLA's school of medicine, said that pressures causing people to gain weight are myriad - including rushed lives, high-calorie convenience foods and physical inactivity.
Deliberately implanting memories also "raises profound ethical questions", said Stephen Behnke, director of the ethics office of the American Psychological Association. "Say, for example, we could change a person's belief about their entire childhood," he said. "Would doing so be ethical?"
The food studies are the latest in a string of memory experiments by Prof Loftus, a professor of psychology and criminology at UC Irvine.
Prof Loftus is most famous for her position on recovered memories of childhood sexual abuse. Based on her work, she has suggested that most of these memories were probably false.
She thinks parents could use this strategy to clean up their children's eating habits - get them to eat more broccoli, perhaps, or fewer French fries.
Gregory Stock, director of UCLA's programme on medicine, technology and society, said this might not be the best thing for healthy parent-child relations.
"How would the child feel later on once you told them how you had manipulated them into eating their vegetables?" he said. "If you're going that far, why not use Photoshop to doctor their childhood photos to show them having problematic experiences with junk food?"