Baseline cortical activation to food pictures associated with change in weight, hunger, cognitive restraint, and disinhibition following bariatric surgery

Abstract

Introduction: Recent research suggests that bariatric surgery may be associated with functional brain changes. Baseline functional magnetic resonance imaging (fMRI) food motivation paradigms may reveal particular patterns of brain activation, which could indicate successful outcomes in weight and other behavioral outcomes following bariatric surgery. The aim of the present study was to determine if activation to food images during a baseline fMRI food motivation paradigm is associated with post-surgical laparoscopic adjustable gastric banding (LAGB) outcomes. We hypothesized that areas previously implicated in food motivation and reward, as well as, cognitive control(inferior, middle, medial superior prefrontal cortex (PFC))would be associated with changes in weight, hunger, cognitive restraint, and disinhibition. Methods: 18 participants viewed food and non-food pictures from a well-established food motivation paradigm during an fMRI scanning session prior to LAGB surgery. Weight and three factor eating questionnaire (TFEQ) scores on cognitive restraint, disinhibition, and hunger were assessed pre-surgery and three and six months post-surgery. fMRI data were analyzed using Brain Voyager QX statistical package. Results: Whole brain analyses, corrected for multiple comparisons, were performed to analyze the relationship between pre-surgical brain activation and subsequent weight loss. Increased activity in frontal regions associated with cognitive control (medial, middle, superior frontal gyrus), with the exception of inferior frontal gyrus, was associated with more weight loss following LAGB. Increased activity in posterior cingulate cortex (PCC) was also associated with greater weight loss post-LAGB. In contrast, decreased brain activity to food cues in frontal areas related to control(inferior, middle, medial, and superior frontal gyri)and increased activity in areas related to reward and motivation (PCC) at baseline was associated with greater improvement in hunger, cognitive restraint, and disinhibition following surgery. Discussion: This is the first study to use fMRI to predict LAGB outcomes. We found that neural activity in previously established regions associated with food motivation, visual attention, and higher order processing predict weight loss following bariatric surgery. These preliminary findings highlight the role of neural circuitry in the success and maintenance of weight loss and suggest a possible future use of fMRI in screening LAGB surgery candidates.