Age and body mass index are associated with dorsolateral prefrontal cortex activation in response to unhealthy food cues

Unhealthy food cues are omnipresent and promote overconsumption. Although childhood obesity rates are increasing, there is no strict regulation of the marketing of unhealthy foods towards children. This is problematic since the human brain, especially areas important for cognitive control, continues to develop into the 30s. It is not known in how far the brain response to unhealthy food cues varies with body mass index (BMI) and age. To investigate this, 168 children (10-17 y) and 182 adults (30-67 y) from the European IDEFICS cohort were scanned with the use of fMRI while viewing pictures of healthy and unhealthy foods. Children exhibited lower activation in the right dorsolateral prefrontal cortex (dlPFC) compared to adults when exposed to unhealthy food cues. Across all age groups, individuals with higher BMI demonstrated reduced activation in the middle cingulum in response to unhealthy food stimuli. Lastly, the relation between BMI and brain activation in response to unhealthy compared with healthy food stimuli varied with development: in children, higher BMI was correlated with decreased activation in right anterior insula and right dlPFC, whereas no such relationship was observed in adults. These findings suggest that children with higher BMI may be particularly vulnerable to unhealthy food cues. In this light, the lack of regulation regarding unhealthy food marketing targeted at children is concerning, especially considering the global increase in obesity rates.