Development and psychometric validation of a questionnaire on health-oriented dietary behaviors with indirect sustainability implications among Iranian adults: a Theory of Planned Behavior approach

This study aimed to develop and validate a TPB-based questionnaire on Health-Oriented Dietary Behaviors with Indirect Sustainability Implications (HODB-ISI) among Iranian adults. This study was conducted on 457 adult participants. The questionnaire was developed, and its psychometric properties were evaluated. The final version included 40 items across 5 subscales. Confirmatory Factor Analysis (CFA) supported the hypothesized 5-factor structure and yielded acceptable fit indices (RMSEA = 0.078, CFI = 0.87). The overall scale demonstrated good internal consistency (alpha = 0.85) and appropriate test-retest reliability (ICC} = 0.79). The validated HODB-ISI questionnaire reliably assesses health-oriented dietary behaviors with indirect sustainability implications within the TPB framework.