Methods: In this clinical trial study, 98 participants were randomly allocated to an HBM group (n = 48) and a control group (n = 50). The HBM group received an audiovisual compact disc (CD) that contained information about nutritional behaviour of colorectal cancer (CRC) prevention based on HBM that lasted 45 min. Both groups completed questionnaires regarding demographic factors, knowledge and HBM constructs, and a three-day dietary recall at the beginning of the study, 1 week after, and 3 months after the education. The outcome of this study was measured by the amount of food servings consumed and dietary micronutrient intake.

Results: At the baseline, there were no significant differences between groups regarding demographic factors. Findings showed that self-efficacy (P < 0.001), severity (P < 0.001), and benefits (P < 0.001) were perceived to be higher, and knowledge (P < 0.001) was increased in the HBM group compared to control group 3 months after education. There was a significant increase in fruit and vegetable (P < 0.001) and dairy (P = 0.001) intake and a significant decrease in red meat servings (P = 0.016) in the HBM group compared to the control group. Also, intake of vitamin D (P < 0.001), folate (P < 0.001), calcium (P = 0.008), and dietary fibre (P < 0.001) was increased in the HBM group compared to the control group 3 months after education.