Even when people are hard at work, pictures of cookies, pizza and ice cream can distract them and these junk food images are almost twice as distracting as health food pictures, concludes a new Johns Hopkins University study, which also found that after a few bites of candy, people found junk food no more interesting than kale.

The study, which underscores people's implicit bias for fatty, sugary foods, and confirms the old adage that you shouldn't grocery shop hungry, is newly published online by the journal Psychonomic Bulletin and Review.

We wanted to see if pictures of food, particularly high-fat, high-calorie food, would be a distraction for people engaged in a complicated task according to researcher. So researchers showed them carrots and apples, and it slowed them down. We showed them bicycles and thumb tacks, and it slowed them down. But when we showed them chocolate cake and hot dogs, these things slowed them down about twice as much.

As the participants worked diligently, pictures flashed in the periphery of the screen  visible for only 125 milliseconds, which is too quick for people to fully realize what they just saw. The pictures were a mix of images of high-fat, high-calorie foods, healthy foods, or items that weren't food.

All of the pictures distracted people from the task, but researchers found things like doughnuts, potato chips, cheese and candy were about twice as distracting. The healthy food pictures  like carrots, apples and salads  were no more distracting to people than non-foods like bicycles, lava lamps and footballs.

Next, the researchers recreated the experiment, but had a new group of participants eat two fun-sized candy bars before starting the computer work.

The researchers were surprised to find that after eating the chocolate, people weren't distracted by the high-fat, high-calorie food images any more than by healthy foods or other pictures. The researchers wonder now if less chocolate or even other snacks would have the same effect.