The relationship between BMI, self-assessment, and brain processing of food images

Abstract

Several studies have focused on cognitive processing of food-related stimuli in response to the rising obesity rates. Previous research has examined the potential connection between brain responses to pictures of food and body mass index (BMI) using an electroencephalogram (EEG). Findings from these studies are conflicting and may be a result of differences in methodologies. The purpose of this study was to clarify and extend the knowledge about the relationship between BMI, brain activity (specifically, event-related potentials [ERPs]) elicited by food-related stimuli, and self-report of food cravings and hunger. The Late Positive Potential (LPP), the ERP of interest, was chosen as previous studies have supported its use as an index of perception of affective stimuli. Twenty-eight participants viewed pictures of unhealthy food and office furniture while their physiological responses were recorded with an EEG. Participants also responded to several self-report questionnaires and had their height and weight collected in order to calculate their body mass index (BMI). Self-report data of food cravings and hunger was not significantly related to BMI. Analysis of LPP amplitudes of food pictures revealed no predictable relationship with BMI. Additionally, no significant differences were found for LPP amplitudes between participants of low and high BMIs. As an extension of previous research, significant differences were found between LPP amplitudes of food pictures and LPP amplitudes of office furniture pictures, supporting the idea that the LPP is a measure of affective relevance.