Abstract

To evaluate core symptoms of muscle dysmorphia, researchers have been applying the widely used Muscle Appearance Satisfaction Scale (MASS). However, the scale has shown unstable factor structure in several validation studies and is not available for Brazilian college-aged men. We aimed to evaluate psychometric properties of the MASS, testing several factor structures among Brazilian men. Eight models of the latent structure of the MASS were tested using confirmatory factor analyses (CFA) in a sample of 454 Brazilian men, aged 18–35 years. Convergent validity, estimated internal consistency, and 2-week test–retest reliability were assessed. A series of CFA demonstrated that six of the eight tested MASS models showed an adequate fit to the data. However, similar to the original MASS, the Brazilian version was well represented with 19 items and five subscales, which showed a good model fit: χ2/df = 1.34; comparative fit index (CFI) =.99; Tucker–Lewis index (TLI) =.99; standardized root-mean-square residual (SRMR) =.05; root-mean-square error approximation (RMSEA) =.02 (90% confidence interval [.01,.03]; p <.001). This model demonstrated good convergent validity and internal consistency (McDonald’s ω =.85), and 2-week test–retest reliability was strong (intraclass correlation coefficient ranged from.74 to.90). Results support six different factor structures of the MASS for assessing muscle dysmorphia symptoms in Brazilian collegeaged men. We suggest the use of the original five-factor solution of the MASS (i.e., Muscle Checking, Bodybuilding Dependence, Muscle Satisfaction, Substance Use, and Injury) to assess core symptoms of muscle dysmorphia among Brazilian men