Bulimia nervosa can be reliably classified into subtypes based on dimensions of dietary restraint and negative affect. Community and clinical studies have shown that dietary-negative affect subtypes have greater test–retest reliability and concurrent and predictive validity compared to subtypes based on the Diagnostic and Statistical Manual of Mental Disorders (DSM). Although dietary-negative affect subtypes have shown utility for characterizing eating disorders that involve binge eating, this framework may have broader implications for understanding restrictive eating disorders. Objective: The purpose of this study was to test the concurrent and predictive validity of dietary-negative affect subtypes among patients with anorexia nervosa (AN; N = 194). Method: Latent profile analysis was used to identify subtypes of AN based on dimensions of dietary restraint and negative affect. Chi-square and multivariate analysis of variance were used to characterize baseline differences between identified subtypes. Structural equation modeling was used to test whether dietary-negative affect subtypes would outperform DSM categories in predicting clinically relevant outcomes. Results: Results supported a 2-profile model that replicated dietary-negative affect subtypes: Latent Profile 1 (n = 68) had clinically elevated scores on restraint only; Latent Profile 2 (n = 126) had elevated scores on both restraint and negative affect. Validation analyses showed that membership in the dietary-negative affect profile was associated with greater lifetime psychiatric comorbidity and psychosocial impairment compared to the dietary class. Dietary-negative affect subtypes only outperformed DSM categories in predicting quality-of-life impairment at 1-year follow-up. Conclusions: Findings highlight the clinical utility of subtyping AN based on dietary restraint and negative affect for informing future treatment-matching or personalized medicine strategies.