Previous research examined the role of identity confusion and body dissatisfaction in eating disorder symptoms, but an integrative perspective including identity synthesis and positive body image is lacking. The current study used three-wave longitudinal data (T1: N = 403; 52.1% female; Mage = 14.85, SD = 0.89) spanning two years to examine the directionality of effects among identity, internalization of appearance ideals, body image, and eating disorder symptoms, with attention to adaptive mechanisms. Results revealed a maladaptive pathway in which internalizing appearance ideals posed a risk for body dissatisfaction and eating disorder symptoms. Conversely, an adaptive pathway highlighted the potential protective role of positive body image regarding identity formation and internalization of appearance ideals. This study provides further insight into the critical role of appearance ideal internalization in the development of eating disorders and the potential value of positive body image. Future research and prevention/intervention efforts should focus on promoting resilience to appearance ideal internalization and enhancing positive body image in the context of identity struggles and eating disorder symptoms.