Causal model of health literacy in dietary supplement use and sufficient health behavior among working-age adults

BACKGROUND: Sufficient health behavior (SHB) and health literacy in dietary supplement use (HL-DSU) are the key determinants of health status. However, the link between HL-DSU and SHB is not fully understood. Therefore, the objective of this research was to investigate the model and identify the size of its effect on HL-DSU and SHB among adults of working age. METHODS: The study employed a cross-sectional survey design, with cluster random sampling used for the selection of 696 working-age adults ranging from 20–59 years. Data on their SHB, HL-DSU, awareness of dietary supplement advertising (DSA), and social support were collected from August to October 2021 through questionnaires employing a 5-point rating scale. Content validity was determined using item-objective congruence (IOC) values ranging from 0.6 to 1.0 obtained for each item on the questionnaire. The Cronbach's alpha values ranging from 0.93 to 0.96 indicated reliability, while the independent t-test, descriptive analysis, and structural equation modeling (SEM) were performed. RESULTS: SHB is defined as the health-beneficial behaviors based on a balanced lifestyle, utilizing conceptual approaches resulting in positive health outcomes relating to fundamental goals in the use of dietary supplements and other contexts emphasizing sufficiency. The causal model was found to fit the empirical data with an acceptable goodness-of-fit value. The findings indicate that social support, awareness of DSA, and HL-DSU directly affect SHB (Beta of 0.33, 0.20, and 0.13, respectively, p < .05) and could predict 34% of SHB overall. HL-DSU is shown to be significantly and directly impacted by social support and awareness of DSA, with influence coefficients of 0.36 and 0.57, respectively. The variance of HL-DSU can be predicted by these two factors as 67%. CONCLUSION: The establishment of campaign activities to promote awareness regarding the advantage and disadvantages, as well as media literacy of supplementary food products in health centers and communities, should be the focus of healthcare providers.