Search

Objectives: Food intake in obesity has been found to be reward-based and less contingent on homeostatic needs. Accordingly, previous studies investigating neural processing of food cues observed aberrant processing in reward- and control-related brain regions in obesity. To further investigate the relation between homeostasis and food intake, this study investigated the influence of glucose metabolism on the neuronal response during the regulation of food craving in participants with obesity., Methods: Twenty-five normal-weight and 25 women with obesity were examined on two occasions after receiving either water or glucose directly into the stomach using a nasogastric tube. Participants were blinded to the type of infusion and were required to refrain from eating for 16 h before each visit. An event-related fMRI paradigm was used to investigate the effect of intestinal glucose load on the neuronal response during the regulation of food craving., Results: A 2 × 2 mixed-model ANOVA revealed that craving regulation was associated with increased activation in fronto-parietal regions in participants with obesity when compared to healthy controls. However, this effect was observed independently from homeostatic satiety. A regression analysis revealed that the reduction of food craving was related to increased activation in the lingual gyrus in individuals with obesity following the infusion of water., Conclusions: In participants with obesity, the neuronal response during the regulation of food craving is associated with increased neural cognitive top-down control and increased visual food processing. Since this observation was independent from satiety status, our results indicate a reduced influence of homeostasis on neural processing during food craving in obesity. This study was registered on clinicaltrials.org: NCT03075371., (© 2021. The Author(s).)

Background: Restrictive food intake in anorexia nervosa (AN) has been related to an overactive cognitive control network inhibiting intuitive motivational responses to food stimuli. However, the influence of short-term homeostatic signaling on the neural regulation of cue-induced food craving in AN is still unclear., Methods: Twenty-five women with AN and 25 matched normal-weight women were examined on two occasions after receiving either glucose or water directly into their stomach using a nasogastric tube. Participants were blinded to the type of infusion. An event-related functional magnetic resonance imaging paradigm was used to investigate the effect of intestinal glucose load on neural processing during either simple viewing or distraction from food stimuli., Results: Neural differences between patients with AN and normal-weight participants were found during the distraction from food stimuli, but not during the viewing condition. When compared to controls, patients with AN displayed increased activation during food distraction in the left parietal lobule/precuneus and fusiform gyrus after water infusion and decreased activation in ventromedial prefrontal and cingulate regions after intestinal glucose load., Conclusions: Independent of the cephalic phase and the awareness of caloric intake, homeostatic influences trigger disorder-specific reactions in AN. Food distraction in patients with AN is associated with either excessive higher-order cognitive control during physiological hunger or decreased internally directed attention after intestinal glucose load. These findings suggest that food distraction plays an important role in the psychopathology of AN. This study was registered on clinicaltrials.gov with identifier: NCT03075371.