Objective Weak or inconsistent association between obesity and impairment in emotional well-being in population-based samples has led to efforts to identify mediating variables. This study examined the relative importance of body dissatisfaction (BD), loss of control (LOC) eating, and self-rated health (SRH) in mediating the association between obesity and impairment in emotional well-being in a school-based sample of adolescents (boys, n = 437; girls, n = 950). Methods Moderated mediation analysis was employed to assess the relative importance of the putative mediating variables and moderation of mediation effects by sex following the methods suggested by Hayes and coworkers. Results BD and SRH, but not LOC eating, were found to mediate the association between obesity and impairment in emotional well-being. Stronger mediation effects were observed for BD than for SRH. None of these results was moderated by sex. Conclusions The findings suggest that it may be important to target BD in obesity prevention and treatment programs in order to reduce the adverse impact of excess body weight on young people's emotional well-being.