Variation in the obesity risk gene FTO determines the postprandial cerebral processing of food stimuli in the prefrontal cortex

Variation in FTO is the strongest genetic determinant of body weight and has recently been linked with impaired neural processing of food stimuli. However, whether this brain-expressed gene affects neuronal processing of food-related stimuli after ingestion is still poorly understood. In this study, twenty-four participants were examined before, 30 and 120 min after ingesting 75 g of glucose solution or water on two separate days. Functional magnetic resonance imaging (fMRI) during visual food presentation was performed. All participants were genotyped for FTO SNP rs8050136. We detected significant differences between FTO genotypes in the prefrontal cortex 30 min post-glucose load in BOLD-response to food pictures (p=0.0017), while no differences were detected in response to water ingestion or 120 min post-glucose load. Since the prefrontal cortex plays a major role in the inhibitory control of eating, we propose that reduced postprandial activity in FTO risk allele carriers contributes to overeating and obesity.