Eating in Front of a Mirror Can Make Junk Food Less Delicious

Nutrition science is a complicated, ever-changing animal. Some experts believe fat is the enemy, while others suggest eating more of it. The same is true for carbs, alcohol, and caffeine. It’s hard to know what’s healthy and what’s not, although there are some exceptions. A cheeseburger, for example. A piece of chocolate cake. A bag of potato chips. A bowl of ice cream. We eat these foods knowing that they’re not good for us. Now, one researcher says that recognizing that guilt can actually ruin the taste of the food.

Behavioral scientists have something called the objective self-awareness theory, which basically says that seeing yourself—whether physically in a mirror or photograph or mentally through writing—forces you to think about what you're doing and why. Studies have shown that this heightened self-awareness can actually change behavior. People confronted with their own image are less likely to cheat on tests, act on sexual impulses, and stereotype other people.

Marketing expert Ata Jami wondered if raising people’s self-awareness could change the way they ate. Would eating junk food be less enjoyable for people who had to watch themselves do it?

Jami ran four experiments on hundreds of undergraduate volunteers at the University of Utah. All the volunteers were told they would be taste-testing new products.

In the first study, participants were offered a choice between two chocolate bars: one described as “healthy” and the other as “tasty.” They were then left alone in a room with or without a mirror to taste the chocolate. After they finished the chocolate, the volunteers filled out a survey rating the chocolate’s taste. People who had picked the “tasty” chocolate didn’t like it very much—but only when they had to eat it in front of a mirror. Volunteers who sat in rooms without mirrors rated the unhealthy chocolate bar just fine. And mirror or no mirror, the “healthy” chocolate got high marks from every taster.

The second and third studies focused on responsibility. Some study participants were randomly assigned to taste either brownies or dried fruit. Others were told to rank a list of healthy and unhealthy snacks in order of their preference. Then they were randomly assigned brownies or dried fruit anyway, with a cover story that the experimenters had “run out” of the other choices. Some people had ranked brownies or dried fruit highly and actually got what they wanted. Everybody else just ate what they were given.

Choice proved to be an important element. People in mirrored rooms who chose to eat brownies gave the brownies a low grade. But everything tasted just fine to the taste-testers who had asked for something else. In short, people who had to watch themselves eat only disliked eating brownies when it had been their idea in the first place. 

Jami has a theory about why the taste of junk food suffers. In an upcoming paper in the Journal of the Association for Consumer Research, he explains that awareness of our poor choices makes us uncomfortable. In the absence of any obvious cause for the discomfort, he says, we tend to blame whatever’s in front of us. In the first three experiments, study participants had been told to pay attention to how the food tasted. It's only natural that the unpleasant feelings manifested as flavor issues.

To test this idea, he added one more element to the last study: music. Study participants were divided into two groups. Jami piped music into all of the study rooms. Half of the volunteers proceeded as usual with the mirrored taste tests. The other half were told that the experiment was trying to test whether or not music could affect their feelings. All participants got to choose between chocolate cake and fruit salad.

The results for the first group matched those of the other three studies: mirror + junk food = ick. People who ate healthy food thought their food tasted fine, as did people who ate junk food without a mirror. But people in the second group had been primed to pay special attention to the music. Sure enough, volunteers in the mirror/music/cake group rated their cake as perfectly tasty. Jami believes they attributed their unease to the music instead.

Now, there are a few caveats to consider before we conclude that adding mirrors to our dining rooms will make us all thin. First, Jami didn’t measure how much people ate. He just measured how bad it made them feel. For all we know, that uneasy feeling could prompt us to eat more.

Secondly, “healthy” and “unhealthy” are kind of fluid terms, especially in this study. For example, the “healthy” and “tasty” chocolate bars in the first experiment? Those were all the same chocolate bars. The experimenters just called them different things. So it’s not necessarily that eating unhealthy food makes us uncomfortable—it’s eating food we think is unhealthy.

Lastly, Jami is not sure how it will work with actual meals, since people often eat healthy and unhealthy food together. If dinner is a cheeseburger and a salad, does the mirror make only the cheeseburger taste bad? Does the salad also take a hit? Do they both taste fine? Nobody knows.