A core feature of body dysmorphic disorder (BDD) is body image disturbance. Many individuals with BDD experience dissatisfaction with the size and shape of specific body parts and may perceive these features differently from their actual dimensions. However, detailed quantification and analysis of these perceptual differences has not yet been performed. To address this limitation, we applied Somatomap 3D, a digital avatar tool, to quantify body image disturbances by assessing body size estimation (BSE) accuracy and body dissatisfaction.

Somatomap 3D allows users to adjust 27 body parts, such as neck girth, shoulder size and stomach form, to create a digital avatar that reflects their perceived current body size. All users start the task by seeing an avatar with randomly sized body parts, to reduce potential bias if all users began with the same fixed avatar, as some participants’ actual body sizes may be more similar to the starting avatar than others.

Furthermore, comparing these avatars with actual measurements of body size and shape allows us to sensitively quantify the discrepancy between perceived and measured body dimensions, reflecting BSE accuracy and body dissatisfaction.