Functional foods and adult consumers' consumption behavior: Adaptation and comparison of theoretical models



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Functional foods are the fastest growing food market sector. This growth has resulted from consumers’ growing interest in wellness, rapid advances in science and technology, increases in healthcare costs, changes in food laws affecting labeling and product claims, and an increase in the aging population. This study had three parts, study1, study 2, and study 3. The purpose of this three-part study was to explain adult consumers’ consumption behavior with regard to functional foods by adapting and comparing three behavioral theoretical models: Protection Motivation Theory (PMT), Theory of Planned Behavior (TpB), and Expanded Rational Expectations model (ERE). The instrument for the study was developed by the researcher, and it included questions based on fourteen theory constructs adapted from the PMT, TpB, and ERE; an objective nutrition knowledge questionnaire developed from previous research; Gould’s (1988) Health Consciousness Scale; and demographic information. A convenience sample of 465 adults from a Southwestern university completed the final survey questionnaire during April and May 2010. In study 1, the Modified Protection Motivation Theory (MPMT) was assessed and used to examine the relationships among concepts from the theory in regard to functional foods: severity, vulnerability, response-efficacy, self-efficacy, intention, and behavior. Results from structural equation modeling revealed that severity and vulnerability were not significant predictors of intention and behavior. Response-efficacy was a significant predictor of intention but not of behavior. Self-efficacy was the only variable that significantly predicted intention as well as behavior.In study 2, subjective knowledge and health consciousness was added to the Expanded Rational Expectations (ERE) model to develop the Modified ERE (MERE) model in order to measure adult consumers’ intention and consumption of functional foods. Results from structural equation modeling revealed that MERE is a viable model to explain functional foods intention and consumption behavior. The two new concepts had significant relationships with other concepts of ERE. In study 3, three cognitive behavioral theories, Theory of Planned Behavior (TpB), Expanded Rational Expectations (ERE) model, and Modified Protection Motivation (MPMT) theory, were assessed and compared to measure adult consumers’ intention and consumption behavior of functional foods. Results from structural equation modeling showed that MPMT is the best model to explain functional foods intention and consumption behavior, while the other two models had acceptable fit to the data. Moreover, functional foods consumer profiles were identified based on MPMT concepts. Outcomes of cluster analysis produced two mutually exclusive consumer groups: Health-Oriented and Uniterested group. Results of discriminant analysis confirmed that MPMT constructs correctly classified 97.3% of participants into the two groups identified by the cluster analysis. Outcomes of the study will benefit the food industry (or food service industry) in terms of target marketing, new product development, and successful market performance.