The images in food advertising are crafted with enough cunning to make any item, no matter its well-known deficiencies, appear tempting. The average American is bombarded with these visual seductions, and everything looks delicious.
In an article to be published next month in one of the leading journals in the nutrition field, researchers report the results of an experiment in which subjects were shown commonly advertised food items -- ice cream sundaes, pizza, french fries and other high-calorie treats. Just before seeing each of those food items, however, the subjects were presented for a fraction of a second with a disgusting image -- a cockroach, vomit, a burn wound. Because the disgusting images were appeared so briefly, the subjects had no conscious memory of them.
Even though the disgusting image was fleeting, however, the brain appears to have associated the food image that followed with a feeling of disgust. Immediately after seeing the photographs, and again three to five days later, the subjects found those items to be less appealing than they did before.
The power of disgust created by the experiment also seemed to taint all high-calorie treats, even those that were not associated with the disgusting photographs in the experiment.
"This outcome suggests that pairing feelings of disgust with [unhealthy foods] could reduce the likelihood of choosing these foods," according to the paper in the American Journal of Clinical Nutrition.
The approach "could be a successful tactic to combat the onslaught of food cues that promote unhealthy eating," the University of Colorado scientists wrote.
It's impossible to know, of course, whether this might actually put a meaningful dent in our appetites for ice cream.
Yes, the results were, in a statistical sense, significant, and the experiment showed that the disgusting subliminal photographs lowered the degree to which subjects wanted to "eat that food at that moment." As the scientists noted, most grocery store decisions are made in a matter of seconds, so what we actually eat may depend substantially on such fleeting feelings.
But the experiment was small -- 42 people -- and brief. The photo sessions lasted just ten minutes. The scientists also did not measure actual weight loss or any change in eating habits. So whether the feelings measured in the experiment will yield meaningful changes in diet is unknown.
Curiously, too, the effect did not work as well in the other direction - that is, an attempt to make low-calorie foods more appealing appears to have flopped. The scientists flashed pictures of kittens, a smiling baby and a butterfly on a flower before pictures of low-calorie items, such as salads and fruit. Afterward, however, the test subjects were no more likely to want to eat them.
"When it comes to food behavior, disgust can be very powerful," said Kristina Legget, assistant professor in the psychiatry department at the University of Colorado School of Medicine. "Kittens and babies are not as powerful as mutilation and contamination."
The scientists are in search of more persuasive positive images.