Explaining thinness- and muscularity-oriented disordered eating in sexual minoritized men: Longitudinal support for the tripartite influence model

The tripartite influence model (TIM) explains how socially-constructed appearance pressures shape body image ideals and subsequent disordered eating in diverse populations, including sexual minoritized men (SMM). Previous research on the TIM in SMM is cross-sectional. Given the implications of temporal precedence, the omission of longitudinal research on the TIM is a critical gap. Two hundred and twenty-five cisgender SMM (M_age=25.79) were recruited via Prolific at baseline. Participants completed surveys at baseline (T1), three-month follow-up (T2), and six-month follow-up (T3). Prospective serial mediation models examined T2 body-ideal internalization and T2 body dissatisfaction, or T2 appearance comparisons and T2 body dissatisfaction, as serial mediators of links between T1 appearance pressures and T3 disordered eating. Adjusting for baseline age, BMI, and the outcome variable (i.e., disordered eating), greater T1 appearance pressures was associated with greater T2 appearance comparisons (b=.20, p < .001), which was associated with greater T2 thinness-oriented body dissatisfaction (b=.25, p = .02) and, in turn, greater T3 thinness-oriented disordered eating (b=.15, p = .004). Furthermore, greater T1 appearance pressures was associated with greater T2 appearance comparisons (b=.25, p < .001), which was associated with greater T2 muscularity-oriented body dissatisfaction (b=.60, p = .001) and, in turn, greater T3 muscularity-oriented disordered eating (b=.12, p = .02). T2 body-ideal internalization did not significantly mediate prospective associations between appearance pressures and disordered eating. Appearance comparisons and body dissatisfaction may explain prospective links between appearance pressures and disordered eating in SMM. Future research considering unique body-ideal internalization manifestations (thinness and muscularity) may support revisions of the TIM as an explanatory framework of disordered eating among SMM.