Is reduced self-esteem a necessary condition for eating disorder symptoms in adolescence? Preliminary evidence from a necessary condition analysis study

Purpose: Eating disorder (ED) symptoms are common psychopathological manifestations, with significant impacts on quality of life, particularly among female adolescents. Despite the high mortality rates of full-blown EDs (5–20%), the mechanisms underlying vulnerability remain poorly understood. Traditional approaches primarily examine probabilistic sufficient factors (i.e., regression coefficients); however, these models fail to accurately predict ED symptoms onset in non-clinical populations. This study shifts focus to necessary conditions—factors whose absence precludes the development of the outcome—using necessary condition analysis (NCA), a novel methodological approach. Methods: We examined whether lower self-esteem is a necessary condition for restriction-oriented cognitions (Drive for Thinness), dissatisfaction about one's body (Body Dissatisfaction), and dysregulated eating behaviors (Bulimia) in female adolescents (N = 84; mean age = 15.74 ± 1.30 years) after 12 months. Results: Results preliminarily indicated that lower self-esteem emerged as a necessary condition for restriction-oriented cognitions (d = 0.25, p < 0.003) and for dissatisfaction with the body (d = 0.22, p < 0.003). However, it was not a necessary condition for dysregulated eating behavior. Conclusions: These findings highlight the potential of NCA to refining theoretical models and clinical interventions by distinguishing necessary conditions from sufficient factors. The study underscores the importance of integrating necessity logic into ED research, offering insights for targeted prevention and personalized care. Level of evidence: Level III: Evidence obtained from well-designed cohort or case–control analytic studies.