Psychophysiological correlates and clinical implications of body-related self-disgust

Body-related self-disgust (BRSD) refers to a specific form of disgust directed towards one’s own body. It is linked to the onset, maintenance, and relapse of eating disorders (EDs). Given its clinical implications, this study aims to characterise BRSD at both psychological and physiological (cardiac and gastric) levels. This ongoing study includes two experimental sessions administered in a counterbalanced order across participants using virtual reality. In one session, BRSD is elicited through the embodiment of avatars with different body sizes: underweight, normal-weight and obese. An additional (control) session explores the psychophysiological correlates of disgust triggered by the observation of disgusting (vs. neutral) video clips, therefore unrelated to one's own body. In both sessions, disgust is measured subjectively via self-reports and objectively through electrocardiogram and electrogastrography. Thirty-nine normal-weight healthy females (mean age 21.9 years; mean BMI 21.5) participated in the study. Preliminary findings suggest that the underweight (BMI 17) and obese (BMI 40) avatars are embodied less, perceived more negatively (higher levels of sadness, guilt and discomfort), and evoke stronger negative emotions compared to the normal-weight one (BMI 21). Notably, BRSD appears most pronounced during the embodiment of the obese avatar. Physiological data show increased heart rate variability (HRV) when watching disgusting videos, with a similar trend found when embodying the obese avatar. Correlational analyses reveal that gastric sensations are positively associated with BRSD when participants embody the underweight and obese avatars. Additionally, BRSD triggered by the underweight avatar correlates positively with cardiac sensations and HRV. Although preliminary, these findings suggest that embodying an obese or underweight body triggers gastric sensations and BRSD accompanied by measurable autonomic changes. Characterising the psychophysiological correlates of BRSD may provide insights into its underlying mechanisms and support its role as a potential transdiagnostic marker of ED psychopathology, informing the development of more targeted interventions.