Psychometric evaluation of the muscle appearance satisfaction scale in a Mexican male sample.

Purpose: The purpose of this study was to determine whether the muscle appearance satisfaction scale (MASS) shows acceptable psychometric properties in Mexican bodybuilders.

Methods: A total of 258 Mexican male bodybuilders were recruited. Two self-report questionnaires, including the MASS and drive for muscularity scale (DMS), were administered. Six models of the latent structure of the MASS were evaluated, using confirmatory factor analysis with maximum likelihood, considering robust Satorra-Bentler correction to estimate the fit of the models to the data.

Results: Similar to the original MASS, the series of CFA confirmed that the Mexican version was well represented with the 17-item five-factor structure, which showed a good model fit [Satorra-Bentler Chi-square (109, n = 258) = 189.18, p < 0.0001; NNFI = 0.91; CFI = 0.93; IFI = 0.93; RMSEA = 0.05 (0.04, 0.07)]. Internal consistency was estimated with McDonald's omega, which was acceptable for the MASS (0.88), and their subscales (0.80 to 0.89), except for muscle checking scale (0.77). Test-retest reliability analysis showed stability of the MASS total as well as of the subscale scores over a 2-week period (intraclass correlation coefficients = 0.75-0.91). Construct validity was demonstrated by a significant positive correlation between MASS and DMS results (r = 0.75; p = 0.0001). These results were similar to those of previous studies, which demonstrate the scale's usefulness.

Conclusions: Our results support the suitability of the MASS and its subscales to measure muscle dysmorphia symptoms in Mexican male bodybuilders.