Stigmatized obese individuals tend to internalize the pervasive weight stigma which might lead to self-discrimination and increased psychopathology. While explicit and implicit weight stigma can be measured using self-report questionnaires and Implicit Association Tests (IAT), respectively, the assessment of self-discrimination relied solely on self-report. The present study sought to develop an IAT measuring implicit self-discrimination (SD-IAT) in samples of obese individuals with and without binge-eating disorder (BED). Seventy-eight individuals were recruited from the community and individually matched in three groups. Obese participants with BED, obese participants without BED (OB), and a normal weight control group without eating disorder psychopathology (HC) were assessed with the SD-IAT and other measures relevant for convergent and discriminant validation. Results revealed significantly higher implicit self-discrimination in the BED group when compared to both OB and HC. Furthermore, significant correlations were found between the SD-IAT with body mass index, experiences of weight stigma, depressive symptoms, and implicit self-esteem. Finally, implicit self-discrimination predicted eating disorder psychopathology over and above group membership, and experiences of weight stigma. This study provides first evidence of the validity of the SD-IAT. Assessing implicit self-discrimination might further increase understanding of weight stigma and its significance for psychosocial functioning among vulnerable obese individuals.

Stigmatized obese individuals tend to internalize the pervasive weight stigma which might lead to self-discrimination and increased psychopathology. While explicit and implicit weight stigma can be measured using self-report questionnaires and Implicit Association Tests (IAT), respectively, the assessment of self-discrimination relied solely on self-report. The present study sought to develop an IAT measuring implicit self-discrimination (SD-IAT) in samples of obese individuals with and without binge-eating disorder (BED). Seventy-eight individuals were recruited from the community and individually matched in three groups. Obese participants with BED, obese participants without BED (OB), and a normal weight control group without eating disorder psychopathology (HC) were assessed with the SD-IAT and other measures relevant for convergent and discriminant validation. Results revealed significantly higher implicit self-discrimination in the BED group when compared to both OB and HC. Furthermore, significant correlations were found between the SD-IAT with body mass index, experiences of weight stigma, depressive symptoms, and implicit self-esteem. Finally, implicit self-discrimination predicted eating disorder psychopathology over and above group membership, and experiences of weight stigma. This study provides first evidence of the validity of the SD-IAT. Assessing implicit self-discrimination might further increase understanding of weight stigma and its significance for psychosocial functioning among vulnerable obese individuals.