Exposure to Written Content Eliciting Weight Stigmatization: Neural Control of Appetite and Food Reward

Abstract

Abstract Objectives Weight bias occurs due to environmental cues, and beyond impacting a person's perception, may have direct physiological effects. Here, fMRI was used to investigate whether exposure to written weight stigmatization content influenced the neural control of appetite and food reward in response to high-calorie (HC), low-calorie (LC) and non-food (NF) images. Relationships were assessed between neural activation, blood glucose, age, body weight, eating behavior (assessed by TFEQ), and subjective pleasantness ratings of food pictures. Methods Overweight/obese individuals were randomized to read either a weight stigma (WS) or control (CT) article, and subsequently underwent brain scans while they rated (via button press) pleasantness of food pictures. Fasting glucose concentrations and TFEQ were measured before reading the article (prior to scanning) and glucose was repeated post-scanning. Results No differences were observed in age or BMI between subjects who read the WS article (6 men, 12 women; mean ± SD, 35.2 ± 13.1y; BMI 30.5 ± 3.0) and CT article (3 men, 15 women, 35.4 ± 11.3y, BMI 30.0 ± 3.3). Whole brain fMRI analysis revealed significant group differences in activation to HC > LC food cues in the following regions: left insula, left thalamus, left inferior occipital gyrus (IOG), right lingual gyrus (LG), and right middle occipital gyrus (P < 0.005 for all). Significant group differences in overall activation to food cues (HC + LC > NF) were observed in the right superior medial gyrus. A significant negative correlation was found between activation in the left IOG and both age (r = −0.38, P = 0.023) and pre-scan glucose concentrations (r = −0.40, P = 0.015). Furthermore, activation in the right LG was positively related to pleasantness ratings for HC foods (r = 0.34, P = 0.040). No significant relationships were observed between activation in any brain region and eating behavior by TFEQ. Conclusions Both younger age and lower fasting glucose concentrations were associated with higher activation in a visual attention region in response to HC foods. Exposure to WS content is associated with increased HC food-related activation in several brain areas implicated in food reward, motivation, attention, and visual memory. WS may increase body weight by increasing motivation for HC food consumption. Funding Sources University of Missouri Brain Imaging Center Type II grant.