Cross-cultural adaptation and psychometric properties of the Chinese version of the Orthorexia Beliefs Scale (OBS)

Background Orthorexia nervosa refers to a pathological obsession with eating “pure” or “healthy” food, and researchers have emphasized the need for psychometrically sound instruments to assess underlying belief systems rather than behavioral outcomes. The Orthorexia Beliefs Scale (OBS) was developed for this purpose, but no validated Chinese version exists. Objective This study aimed to translate and culturally adapt the OBS into Chinese and to evaluate its psychometric properties, including reliability and construct validity, in a Chinese nonclinical sample. Methods The original OBS was translated following standard forward-backward translation procedures and refined through expert review and pilot testing. A total of 352 Chinese participants completed the questionnaire, which was randomly split into two subsamples (N₁ = 152 for exploratory factor analysis; N₂ = 200 for confirmatory factor analysis). Item analysis, internal consistency (Cronbach’s α, McDonald’s ω), content validity (CVI), exploratory factor analysis (EFA), and confirmatory factor analysis (CFA) were conducted. Results Item–total correlations ranged from 0.46 to 0.64. Content validity indices (I-CVI) were high across items, and the scale-level S-CVI/Ave was 0.99. The EFA extracted three factors explaining 50.3% of variance, consistent with the original theoretical structure. CFA results showed acceptable model fit: χ²(167) = 265.66, p < .001, χ²/df = 1.59, CFI = 0.949, TLI = 0.942, RMSEA = 0.053 (90% CI [.041, .065], PCLOSE = 0.328). Cronbach’s α and ω were above 0.80 for the total scale and all subscales. Test–retest reliability (n = 30, two-week interval) yielded intraclass correlation coefficients (ICC) above 0.75. Conclusions The Chinese version of OBS demonstrated strong reliability and validity in a nonclinical Chinese sample. It is a psychometrically sound instrument suited for assessing orthorexia-related belief systems in Chinese populations, laying a foundation for future research and interventions on orthorexia tendencies in China.