Inconsistent results published in previous studies make it difficult to determine the precise effect of consumer knowledge on their acceptance of functional foods. We conducted a systematic review and meta-analysis by identifying and collecting relevant literature from three databases. Of the 1050 studies reviewed, we included 40 in the systematic review and 18 in the meta-analysis. Based on the focus of each included study, we operationally defined knowledge as knowledge of the functional food concept, nutritional-related knowledge, and knowledge of specific functional products. Results from the systematic review indicate that most participants from the included studies had low knowledge, especially nutrition-related knowledge associated with consuming functional foods, and were generally not familiar with the concept of functional foods. Results from the meta-analysis generated a summary effect size (r = 0.14, 95% CI [0.05; 0.23]), measured by the correlation coefficient r, which indicates a small positive relationship exists between consumers' level of knowledge and their acceptance of functional foods. Results from our study demonstrate the importance of increasing consumers' functional foods knowledge to improve their acceptance of such products. Agricultural and health communicators, educators, and functional foods industry professionals should prioritize increasing consumers' knowledge through their communications, marketing, and programmatic efforts.
Keywords: consumer acceptance; functional foods; knowledge.