The health costs of colorectal cancer have increased over the years in Taiwan. The National Health Insurance Administration (NHI) and the Health Promotion Administration of the Ministry of Health and Welfare (MOHW) in Taiwan advocate that people have to change their unhealthy behaviors; however, the number of patients of colorectal cancer is increasing annually. This research discussed the effects of healthy diet advocacy advertisements (ads) on healthy diet behavior intentions as influenced by the interactions between regulatory focus theory (RFT) and message framing effects. Both regulatory focus theory and message framing effect were discussed for the relationship between advertisement and behavior change in many fields, such as health-related behavior, pro-environmental behavior, consumer choice, etc. We executed an experiment with four different types of public health advocacy ads. A 2 (regulatory focus: promotion vs. prevention) × 2 (message framing: gain framing vs. loss framing) two-factor experiment was adopted, and 201 valid participants responded to the questionnaire. Results indicated that if the ad's regulatory focus is promotion focus, viewers' attitudes toward the ad and their behavior intentions are more positive when the slogan of the ad is gain framing rather than loss framing via the multiple analysis of variance (MANOVA), and vice versa. Respondents found the communication easier to comprehend when the ads evoked the respondents' regulatory focus and applied the appropriate message framing, thus improving the efficacy of health-related advertising. We offer suggestions regarding the future use of health-related advertising for the MOHW.
Keywords: attitude toward healthy advertisement; behavior intention; healthy advertisement; message framing; regulatory focus theory.