Weight Stigma Effect on Neural Control of Appetite

The limited data available suggest that exposure to weight-based stigmatization leads to overeating and increased desire for food. In the present study, overweight and obese individuals (BMI from 25-35 kg/m2) who are generally healthy will be randomized to read a weight-stigma article or control article and subsequently scanned to collect fMRI data. These procedures will be employed to accomplish two specific aims. Specific Aim 1: Determine the neural mechanisms involved in exposure to weight stigma on central control of appetite in overweight and obese individuals. To accomplish this aim we will collect fMRI data in study participants when viewing food and scenery pictures after being exposed to either a weight-stigma or control article. In addition, participants will complete validated questionnaires to measure perceived weight-stigma experiences and social support for eating and physical activity. Hypothesis: After reading an article depicting weight stigmatization, when shown pictures of food in the fMRI scanner, overweight/obese individuals that perceive themselves as having experienced higher levels of weight stigma and lower levels of social support, will have higher activations of brain regions that control appetite and food reward (amygdala, orbitofrontal cortex, striatum, insula) and reduced activations in brain areas that regulate self-control and decision making (prefrontal cortex and cingulate cortex respectively) compared to a control group that reads a non-weight stigma article. Specific Aim 2: To assess the relationship between activity in appetitive and self-control brain regions and self-reported, eating-related behavior. To accomplish this aim, participants will also complete questionnaires that measure self-reported food intake motivation (dietary restraint, disinhibition and hunger), appetitive responses, and mood. Hypothesis: Higher activations in appetite and reward regions and lower activations in self-control brain regions will be correlated with higher levels of dietary disinhibition, hunger/appetite, and dietary restraint.