Why Do We Eat Junk Food When We’re Bored?

For such a tedious emotion, boredom is surprisingly powerful stuff. It’s frequently cited as a motivation for crime and violence, especially among teenagers. Another one of boredom's unfortunate effects is the way it seems to cause people to make a beeline for the snack drawer, pantry, or freezer. Scientists who conducted a recent study on this phenomenon say the discomfort of boredom drives us to seek out dopamine-stimulating sweet or fatty foods. They present their research results this week at the Annual Conference of the British Psychological Society.

Researchers at the University of Central Lancaster in the UK designed two experiments to find out how our outdated reward systems respond to boredom. In the first experiment, 52 participants were instructed to copy down the same group of letters over and over. Once the participants were good and bored, the researchers gave them a questionnaire about their favorite foods.

Participants in the second experiment watched one of two videos in a room stocked with both healthy and unhealthy snacks. One video was funny, while the other was boring.

Sure enough, participants in the first task expressed more interest in junk food than healthy food on their questionnaires after finishing the boring letter-copying task. Potato chips, sweets, and fast food topped the list of favorites. (These also happen to be some of the most addictive foods out there. And where does addiction live? In your brain's reward center.)

Likewise, people in the boring video group ate significantly more unhealthy food than the participants who got to watch something interesting.

Researcher Sandi Mann was unsurprised by her results, which “are in line with previous research suggesting that we crave fatty and sugary foods when we are bored,” she said in a press statement. “This strengthens the theory that boredom is related to low levels of the stimulating brain chemical dopamine and that people try to boost this by eating fat and sugar if they cannot alleviate their boredom in some other way.”

Our bodies, including our brains, evolved to ensure that we get fed, sheltered, and mated. To ensure that we make those activities a priority, our bodies produce feel-good chemicals like dopamine and serotonin when we do something “right.”

Unfortunately, what was necessary and right for our prehistoric ancestors may not be great for us. The fats and sugars that were so precious and rare for cave-dwellers are more than readily available these days, stuffed into every processed food imaginable. And when we eat these kinds of foods, as we so often do, our brains reward us.

"People designing health education campaigns to encourage us to make healthier food choices need to take boredom, including boredom in the workplace, into account," Mann said. "Bored people do not eat nuts."