Validation of the Body Appreciation Scale - 2, and its short form in Danish youth (aged 15-25) with subgroup score comparison.

Research interest in positive body image has increased in recent years, marking a shift away from a traditional focus on negative body image. We aimed to examine the psychometric properties of the Body Appreciation Scale 2 (BAS-2) and its short form (BAS-2SF) in a Danish sample aged 15-25 years and explore their level of measurement invariance across age and gender groups. In this cross-sectional study, respondents completed an online survey that was disseminated through social media, newsletters, and schools. The survey included the BAS-2, BAS-2SF, and related scales to explore convergent validity. We conducted a Confirmatory Factor Analysis (CFA) to test unidimensionality, we tested internal consistency, and measurement invariance across genders (men, women, other) and age groups (15-20, 21-25). We analyzed 2005 complete responses. Of these, 471 were men, 1435 were women, and 99 were individuals of other gender identities. The mean age of participants was 21.7 years (SD = 2.5). CFA supported unidimensionality for BAS-2 and BAS-2SF, and internal consistency was also supported. Fit indices supported scalar to strict measurement invariance across age and gender groups. Correlations with related scales supported convergent validity. Group comparison showed that men reported the highest body appreciation, followed by women, and individuals of other gender identities. The differences between age groups were insignificant. The BAS-2 and BAS-2SF exhibited good psychometric properties in a Danish sample aged 15-25 years.