Assessment of attitudes toward functional foods based on theory of planned behavior: Validation of a questionnaire

Abstract

Background: The objectives of this study are to construct a cultural adopted questionnaire for evaluation of consumer's attitudes toward functional foods among Iranian's population according to Theory of Planned Behavior (TPB) and to investigate the attitudes toward vitamin enriched foods (VEF). Methods: Participants were students of Birjand University of Medical Sciences (BUMS). Exploratory factor analysis (EFA), Confirmatory Factor Analysis (CFA) and reliability assessment were performed. The construct validity of questionnaire determined by EFA and confirmed by CFA. Results: The overall Cronbach's alpha of questionnaire was 0.78. The three domains of TPB model were significantly associated with the total score of attitude toward functional foods questionnaire (AFFQ). Attitudes and subjective norms could successfully predict the consumption of VEF (p < 0.023 and p < 0.001, respectively), but perceived control construct could not perform the prediction (p < 0.219). Conclusion: AFFQ is a valid and reliable instrument to measure the attitudes of consumers toward consumption of functional foods in Iran.