Body Image Disturbance and Body Dissatisfaction in Sisters of Adolescent Girls with Anorexia Nervosa: A Narrative Review and a Preliminary Study

Background: Body image disturbance (BID) involves a distorted perception of one’s body, whereas body dissatisfaction (BDS) reflects negative affective evaluation of body appearance. Both are central features of eating disorders such as anorexia nervosa (AN), but their expression in siblings of affected individuals remains underexplored, particularly in younger populations. Methods: This cross-sectional preliminary study included 53 full sisters of adolescent patients with severe AN treated in a tertiary hospital. Participants underwent anthropometric assessment and completed standardized measures of BID, BDS, physical activity, eating-related attitudes, perfectionism, anxiety, and depressive symptoms. Results: Participants exhibited marked body size overestimation (mean relative BID = +45.2%), with 64.2% classified as high overestimators and 3.8% as underestimators. Overestimation was most pronounced in the waist, chest, and calves. BID was not significantly associated with BDS or with anthropometric measures, including body mass index. BDS showed significant positive correlations with depressive symptoms and self-oriented perfectionism, whereas BID was positively associated with physical activity. No significant associations were found between BID or BDS and age, socioeconomic status, or birth order. Conclusions: Sisters of adolescents with severe AN show substantial perceptual distortion of body size without corresponding levels of body dissatisfaction, suggesting partial independence between perceptual and affective components of body image. These findings identify a potentially vulnerable group and highlight the need for longitudinal studies to clarify mechanisms and inform preventive strategies.