Getting a Fix from Digital Screens and Food Rewards

Is it mere coincidence that the rise of digital screen time has moved in parallel with the rise in obesity? A new paper points to a possible explanation. Researchers studied the effects of multitasking on digital screens by college students. They found a close relationship between heavy multitasking and and a stronger brain response to rewarding food cues.

Could it be that this multitasking favors more active reward circuits in the brain?

A Pair of Studies

In a pair of studies, Richard Lopez and colleagues examined the interaction between digital media multitasking, obesity, and the brain response to food cues. Through the course of these studies, they found support for three findings.

First, they saw that individuals who did a lot of this multitasking had a higher risk for excess weight and obesity. Next they conducted functional MRI on a subset of the subjects in the first study. In those scans, they saw responses to appetizing food cues heightened in reward circuits of high multitaskers.

And then finally, they also tracked movements of these individuals around campus over the course of the semester. They found that the high multitaskers were spending more time in campus eateries.

A Correlation and a Theory

Lopez et al remind us that digital media offers stimulation that is new to human brains. They suggest that we may be overwhelming our cognitive circuits:

There also may be unrecognized, harmful effects of indulging in media multitasking, such as impaired functioning of brain networks associated with cognitive control and attention. The available evidence, although tentative, indicates that media multitasking may be an important contributing factor in the recent obesity epidemic, possibly via altering the balance between control and reward regions.

Of course, these are very tentative observations. At this point, they are merely correlations. But we do know that excessive screen time does predict more obesity risk. And we know that interventions to reduce screen time can reduce the risk of excessive weight gain.

So this research fits into a bigger picture. Further, it suggests that our digital media diet might deserve closer consideration. If we pay attention only to food, we might miss an important part of the story.

Click here for the study by Lopez et al, here for additional reporting, and here for perspective on screen time and obesity in youth.

Screen Encounter, photograph © Georgie Pauwels / flickr

Subscribe by email to follow the accumulating evidence and observations that shape our view of health, obesity, and policy.

April 7, 2019