Objective: The present study developed the Weight Bias Internalization Scale (WBIS), an 11-item measure assessing internalized weight bias among the overweight and obese.

Methods and Procedures: An Internet sample was recruited through online community discussion groups and snowball sampling via e-mail. Women (n = 164) and men (n = 34) with a BMI >25 kg/m2 completed the WBIS and the Antifat Attitudes Questionnaire (AAQ), as well as measures of self-esteem, body image, mood disturbance, drive for thinness, and binge eating.

Results: Results indicate that the WBIS had high internal consistency (Cronbach's α = 0.90) and correlated significantly with antifat attitudes but was not a completely overlapping construct (r = 0.31). The scale showed strong partial correlations with self-esteem (r = −0.67), drive for thinness (r = 0.47), and body image concern (r = 0.75), controlling for BMI. Internalized weight bias was also significantly correlated with measures of mood and eating disturbance. Multiple regression analyses were conducted using WBIS scores, antifat attitudes, and BMI as predictor variables of body image, mood, self-esteem, and binge eating. WBIS scores were found to significantly predict scores on each of these measures.

Discussion: The WBIS showed excellent psychometric properties and construct validity. The study highlights the importance of distinguishing antifat attitudes toward others from internalized weight bias, a construct that may be closely linked with psychopathology.