Researchers say that junk food is much more distracting than healthful foods.
In fact, the study researchers — from Johns Hopkins University in Baltimore, MD — found that food in general has the ability to divert our attention, but when it comes to candy vs. kale, the former always wins.
Study co-author Corbin A. Cunningham, of the Department of Psychological and Brain Sciences at Johns Hopkins University, and colleagues recently reported their findings in the journal Psychonomic Bulletin and Review.
As English writer Virginia Woolf once said, "One cannot think well, love well, sleep well, if one has not dined well." Many of us have a similar relationship with food – that feeling of contentment and joy after eating a delicious meal or tasty snack.
Unfortunately, we seem to be more drawn to foods that, in excess, can harm our health. This is because foods that are high in fat or sugar are more likely to activate the brain's reward system, making those high-calorie treats more appealing than foods that we know are good for us.
But how distracted are we by calorie-dense treats? And are they more distracting than healthful foods? Cunningham and colleagues wanted to find out.
Subjects twice as distracted by junk food
The study consisted of two experiments. The first experiment included 18 participants who were required to engage in a "distraction paradigm" exercise, which aimed to determine how food diverted attention from a complex computer test.
In the task, food- and non-food-related images appeared on the screen for just 125 milliseconds — which the researchers say is too fast for people to fully comprehend what they have seen but is long enough for their brains to process the visual information.
The food images included pictures of high-fat, high-calorie products — such as chocolate, cheese, candy, and hot dogs — as well as healthful foods, such as carrots and apples.
The researchers found that all images diverted the subjects' attention from the computer test. However, the images of the high-fat, calorie-dense foods were found to be twice as distracting as the images of healthful foods and non-food objects.
"This suggests that participants rapidly and implicitly assessed the nutritional value of the distractor images presented to them, even when they were entirely irrelevant," says Cunningham.
Don't go to the grocery store hungry
For the second experiment, the researchers enrolled 18 new subjects. The task was the same as in the first experiment, except that the participants consumed two small candy bars beforehand.
The researchers found that these subjects were no more distracted by the images of high-fat, high-calorie foods than images of healthful foods or non-food images.
Study co-author Howard E. Egeth, also of the Department of Psychological and Brain Sciences at Johns Hopkins University, speculates that consuming the candy bars prior to the experiment reduced participants' cravings for tasty treats.
"Recent research has shown that when an ordinarily rewarding stimulus such as chocolate is devalued," he says, "attention is no longer oriented towards this reward-associated stimulus."
So, what are the implications of this study? The researchers believe that their results certainly back up the theory that you should avoid going to the grocery store on an empty stomach.
"You would probably make choices that you shouldn't or ordinarily wouldn't," says Cunningham.