Objective: Cognitive-behavioral and interpersonal models of loss of control (LOC) eating have been underexplored in adolescents. Methods: By using data from community-based adolescent girls assessed annually over 4 years, the cognitive-behavioral (n = 416) and interpersonal (n = 418) models were examined by using a regression-based bootstrapping approach. Results: Body dissatisfaction at 14 years prospectively predicted LOC eating at 18 years, both directly (direct effect = −0.039; SE = 0.017; P = 0.02) and indirectly via dieting (indirect effect = −0.010; 95% CI: −0.022 to −0.003). Interpersonal functioning at 14 years was negatively associated with negative emotionality at 17 years, which, in turn, was prospectively associated with LOC eating at 18 years (indirect effect = 0.001; 95% CI: −0.001 to −0.0003); however, the direct association between age 14 interpersonal functioning and age 18 LOC eating was not significant (direct effect = −0.001; SE = 0.001; P = 0.47). Conclusions: These findings support the cognitive-behavioral model, and partially support the interpersonal model, with the latter findings implying that over time, negative emotionality may promote LOC eating independent of the effects of prior social functioning. Prevention and early intervention efforts for LOC eating may benefit from integrating these theoretical frameworks.