Interoceptive Processing across Modalities in Disordered Eating Behavior

Disordered eating behaviors are prevalent in both clinical and non-clinical populations. Early intervention is crucial to prevent their progression into more severe conditions, such as eating disorders (EDs). Altered interoceptive processes, especially the awareness of emotional states and the perception of hunger and satiety, represent a key transdiagnostic feature of EDs and constitute important targets for intervention. This thesis investigated interoceptive processes as underlying mechanisms of disordered eating and EDs using psychophysiological, behavioral, and self-report measures. The main objectives were to (1) develop and validate a self-report measure to assess ED-specific interoceptive perception (EDIP) and (2) provide a comprehensive assessment of interoceptive processes in two organ systems relevant to eating behavior, i.e. the cardiovascular and gastrointestinal systems. Studies 1-3 focused on the development and validation of the EDIP Questionnaire (EDIP-Q), a 25-item questionnaire comprising four subscales (i.e., Emotions, Hunger, Satiety, and Discrimination) to assess the ability to perceive and differentiate between emotions, hunger, and satiety. The EDIP-Q, available in German, English, and French, demonstrated sound psychometric properties across all language versions. Using the EDIP-Q, descriptive profiles of EDIP were established for anorexia nervosa (AN), bulimia nervosa (BN), and binge-eating disorder (BED). While individuals with self-reported EDs reported similar difficulties in perceiving emotions, those with AN reported lower sensibility to hunger, higher sensibility to satiety, and fewer difficulties in discriminating between emotional states and hunger compared to individuals with BN and BED. In contrast, the profiles of BN and BED were opposite to that of AN.
Studies 4 and 5 examined interoceptive processes in individuals with recurrent binge eating episodes (BEEs) across the cardiovascular system (Study 4) and the gastrointestinal system (Study 5). The findings revealed profiles of interoceptive alterations in individuals with recurrent BEEs. These alterations were, however, not consistent across modalities. In conclusion, the evidence highlights the differential contribution of interoceptive processes to ED symptoms. Future research is encouraged to assess interoceptive processes across multiple levels and organ systems, investigate how these alterations contribute to the etiology and maintenance of disordered eating behaviors, and develop targeted interventions aimed at improving treatment outcomes.