PURPOSE: To compare the effects of after-school sedentary versus active play on activation in the reward and cognitive control regions of the brain to pictures of high- and low-calorie foods. METHODS: 32 children (12 girls, 20 boys; age 8.7 ± 0.5 years; height 137.9 ± 6.9 cm; weight 32.4 ± 6.2 kg) 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 in reward and cognitive control regions of the brain were assessed using functional magnetic resonance imaging (fMRI) while participants completed a go/no-go task involving pictures of high- and low-calorie foods. General response inhibition was measured by the Stroop task. Hunger was measured upon arrival to the testing facility and just prior to fMRI scans. Mixed effects models were used to evaluate main and interaction effects. RESULTS: Significant stimulus by condition interactions were found in the right superior parietal cortex, right postcentral gyrus and accumbens area (p <<> 0.05). High- versus low-calorie pictures of food elicited significantly different activation bilaterally in the orbitofrontal cortex (p <<> 0.01). Stroop task performance diminished significantly following the sedentary condition compared to the active condition (F = 6.79, p <<> 0.01). Subjective feelings of hunger were not different between conditions at any point. CONCLUSION: Sedentary behavior significantly decreased response inhibition and brain activation to pictures of high-calorie foods in areas of the brain important to the modulation of food intake. Decreased attention, reward, and response inhibition, following sedentary behavior, may contribute to disinhibited eating that can lead to overweight and obesity.



College and Department

Life Sciences; Exercise Sciences

Date Submitted


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sedentary behavior, response inhibition, fMRI, go/no-go task, obese