Weight misperception and its associations with eating disorder symptoms over the course of residential eating disorder treatment.

Objective: Although individuals with eating disorders (EDs) often experience significant body dissatisfaction and perceptual body image distortions, the presence and impact of weight misperception in clinical samples have been minimally examined. The aims of this study were to quantify weight misperception in individuals with EDs, examine whether weight misperception predicts ED severity at treatment discharge, and explore changes in weight misperception across treatment.

Method: Participants were 98 women seeking residential treatment for their ED who reported weekly on their perceived weight. Objectively measured weight was subtracted from perceived weight to determine weekly "weight misperception." Participants completed the Eating Disorder Examination Questionnaire (EDE-Q) at intake and discharge to assess ED severity. Weight misperception at intake and change in weight misperception over treatment were examined as predictors of ED pathology at discharge.

Results: Approximately 74.5% of the sample overestimated their weight, with an average weight misperception of 2.7 (SD = 5.6) pounds (1.2 kg; SD = 2.5). Weight misperception spanned from -6.2 to 43.6 pounds (-2.8 to 19.8 kg) and did not differ based on ED diagnosis. On average, weight misperception increased throughout treatment. Greater weight misperception at intake as well as greater increases in weight misperception over treatment significantly predicted EDE-Q scores at discharge.

Discussion: Findings highlight that weight misperception is not limited to underweight patients. Misperceiving one's weight may predict symptom severity across a range of EDs, and future research is needed to examine whether targeting weight misperception during residential treatment could improve treatment outcomes for individuals with EDs.