Cross-validation of the body appreciation scale-2: invariance across sex, body mass index, and age in Mexican adolescents.

Cross-validation is a useful strategy to address problems associated with the post hoc model fitting. The aim of this study was to cross-validate the BAS-2, in two samples (Calibration and Validation Samples), using an invariance testing strategy. 1127 Mexican adolescents (508 males and 619 females), aged 11-19 years (M = 15.41, SD = 2.30), allocated in two samples (n = 672; n = 455) completed the Mexican version of the BAS-2, along with other body image-related instruments. The cross-validation supported the generalizability of the one-factor respecified model of the BAS-2. The measure was invariant across body mass index and age, but not across sex. Internal consistency and test-retest reliability (a three-week period between each test) was excellent. In support of the validity of the BAS-2, it was positively associated with scores on body esteem, but negatively with body mass index, drive for thinness, and body dissatisfaction. Normal-weight and young adolescents groups showed higher body appreciation than excess-weight and late adolescents groups, respectively. Considering these findings, it is reasonable to conclude that the BAS-2 is a reliable and valid instrument to assess body appreciation in Mexican adolescents. LEVEL OF EVIDENCE: Level V, cross-sectional, descriptive study.