The purpose of this study was to examine the effects of after-school sedentary screen time on children’s brain activation in reward and cognitive control regions in response to pictures of high- and low-calorie foods.
Thirty-two children participated in a randomized crossover study with counterbalanced treatment conditions. Conditions took place on separate days after school and included three hours of active or sedentary play. After each condition, neural activation was assessed using functional magnetic resonance imaging (fMRI) while participants completed a go/no-go task involving pictures of high- and low-calorie foods. Mixed-effects models were used to evaluate the main effects and interactions.
Significant stimulus (high vs. low-calorie foods) by condition (active play vs. sedentary) interactions were found in the right superior parietal cortex, right postcentral gyrus, anterior cingulate cortex, and nucleus accumbens area (P’s < 0.05). High- vs low-calorie pictures of food elicited significantly different activation bilaterally in the orbitofrontal cortex. Subjective feelings of hunger were not different between conditions at any point.
Sedentary screen time was associated with significantly decreased activation in areas of the brain related to reward, attention, and impulse control to pictures of high-calorie foods in areas of the brain. Decreased activation in areas of the brain related to the modulation of food intake following sedentary screen time may contribute to disinhibited eating that can lead to overweight and obesity.