Stages of change concept of the transtheoretical model for healthy eating links health literacy and diabetes knowledge to glycemic control in people with type 2 diabetes

Aims Health literacy has been recognized as a key construct associated with clinical outcomes; however, few studies have explored the mechanism underlying the association. The transtheoretical model (TTM) has long been considered a useful conceptualization in the process of intentional behavior change. Stages of change lies at the heart of the TTM as studies of change have found that people move through a series of stages when modifying behavior. This study focuses on the role of knowledge and stages of change (SOC) as serial mediators linking health literacy to glycemic control. Methods In this cross-sectional survey, a total of 232 patients with type 2 diabetes participated in this study. Participants completed questionnaires for assessing health literacy, readiness to consume healthy foods, and a dietary knowledge test specific to diabetes. Results Low health literacy was significantly associated with worse glycemic control. Statistical evaluation supported the serial mediation model, in which knowledge and SOC formed a serial mediation chain that accounted for the indirect effect of health literacy on glycemic control. In other words, dietary knowledge significantly motivated participants to move into the later stages of behavior change, which in turn improved the outcome of glycemic control. Conclusions The results indicate that the ordering of mediators in the pathway between health literacy and health outcome may be complex, help explain the conflicting results of the past, and form a basis for the development of interventions promoting self-management of diabetes through glycemic control.