Toward a triadic approach in eating disorders: investigating the contribution of the reflexive, affective and interoceptive systems in a clinical data cohort

BACKGROUND: Eating disorders (ED) are disabling conditions increasingly conceptualized as addictive disorders. While food addiction (FA) is well documented in bulimia nervosa (BN) and binge-eating disorder (BED), its mechanisms in anorexia nervosa (AN) remain unclear. The triadic model of addiction-encompassing reflexive, affective, and interoceptive systems-offers a relevant framework to investigate FA across EDs. The current study aimed to test to what extent these three components of addiction contribute to FA in patients with ED. METHODS: The sample included 115 patients (mean age = 28.41 years, SD = 11.64; 91% female) diagnosed with either AN (restrictive: n = 38; binge-eating/purging type: n = 32), BN (n = 29), or BED (n = 16). Participants completed the Emotional Appetite Questionnaire, the interoceptive subscale of the Eating Disorder Inventory-2, the Detail and Flexibility Questionnaire, and the Yale Food Addiction Scale 2.0. In the present analyses, FA was operationalized using the continuous total score reflecting FA symptom severity. Additional analyses using the symptom-count and diagnostic scoring procedures yielded comparable results. Linear and multinomial logistic regressions were used to test the associations between FA and the three systems, and their ability to distinguish diagnostic groups. RESULTS: When considered separately, interoceptive difficulties (r = .54), negative emotions (r = .47), and cognitive inflexibility (r = .33) were all associated with higher FA (all ps < 0.001). However, in the joint model, only interoception (β = 0.39, p < .001) and negative emotions (β = 0.33, p = .005) remained significant predictors, whereas cognitive flexibility had no significant effect. These effects did not differ significantly between diagnostic groups. The affective system predicted diagnostic (χ²(3) = 21.78, p < .001), but the effect was inconsistent and the overall predictive value was modest (McFadden's R² = 0.11, classification accuracy = 50%). CONCLUSION: Interoceptive and affective systems appear to significantly predict FA across various ED; the reflexive system, as currently measured, seems to play a more limited role. These results highlight the need for more sensitive assessment tools and refined models of ED-related addictive dimensions. Trial Registration NCT03160443, first post 2017-05-03.