The Impact of a Dissonance-Based Prevention Program on Eating Disorder Developmental Trajectories

Randomized trials provide support for the Body Project, an eating disorder prevention program wherein young women with body image concerns critique the thin ideal, which putatively reduces pursuit of this unrealistic ideal as a result of dissonance-induction. Despite medium to large effects, some Body Project participants subsequently develop an eating disorder during 3-year study follow-up, suggesting intervention or recruitment procedures could be improved. This study was the first to delineate the heterogeneous pathways of eating disorder symptom trajectories among Body Project versus control group participants during 3-year study follow-up. This study also investigated the predictive role of baseline risk factors on qualitatively distinct developmental pathways of eating disorder symptomology, helping to explain contributing factors to suboptimal Body Project response. Existing data from three randomized controlled trials were combined to examine response trajectories of prevention intervention versus control participants through 3-year follow-up. Group-Based Trajectory Modeling distinguished distinct response trajectories and the impact of prevention on mitigating the developmental course of eating disorder symptoms. The three-group solution for control participants produced the strongest model fit. The resulting trajectories were those of low-stable, moderate-stable, or high-variable levels of eating disorder symptom courses. Dietary restraint and negative affect predicted increased likelihood of membership in the high-risk trajectory. The optimal solution for Body Project participants was a two-group trajectory model with low-decreasing or high-decreasing trajectories, with the moderate-level risk group observed in the control group seemingly deflected by prevention effects. This study also determined the predictive role of risk factors on qualitatively distinct developmental pathways of eating disorder symptomology, confirming the hypothesized impact of thin-ideal internalization, negative affect, and dietary restraint on sub-optimal prevention response. The results of this novel study supplement developmental research regarding eating disorder symptom predictors and course, ultimately informing future design and adaptation of evidence-based eating disorder prevention programs