Objective: In the last decade, body image research has increasingly focused on the distinction between negative and positive body images as separate constructs. Functionality appreciation is a crucial component of positive body image and might be an important source for coping with body image problems. The intervention Expand Your Horizon (EYH; Alleva et al. 2015a) was designed to increase functionality appreciation and has demonstrated positive effects on body image across different adult populations. In the current research, we investigated the short-term effects of a single-session EYH in adolescent girls with an eating disorder.

Method: Fifty-eight adolescent girls with an eating disorder were randomly assigned to the EYH condition or an active control condition. Different aspects of positive and negative body images were assessed before and after the intervention.

Results: Participants in the experimental condition showed higher scores than the control condition on positive body image after the writing exercise, but no effects on negative body image were found. Exploratory analyses showed that improvements in the positive body image remained stable 15–30 min after the writing exercise.

Discussion: These outcomes suggest that writing about body functionality leads to direct increases in positive body image but not to decreases in negative body image. An important step for future studies would be to test the full three-session version of EYH and investigate its effects over the longer term. This could help to determine the robustness of the present findings and the potential of EYH as a complementary intervention to existing treatments.d text (2025).