Associations of health literacy, dietary decisional balance, and dietary self-efficacy with dietary self-management behaviors in patients with type 2 diabetes mellitus: a cross-sectional study

Background Dietary self-management is essential for glycemic control in type 2 diabetes mellitus (T2DM), yet the factors associated with it and their interrelationships remain underexplored. Objective To examine the associations of health literacy, dietary decisional balance, and dietary self-efficacy with dietary self-management behaviors in patients with T2DM. Methods This was a cross-sectional study conducted in four endocrinology departments of four tertiary hospitals in Guangdong province from September 2022 to January 2023. A total of 387 inpatients diagnosed as T2DM were consecutively sampled. Health literacy was measured using the Health Literacy Scale (FCCHL). Dietary decisional balance was assessed using the Dietary Decisional Balance Scale, dietary self-efficacy using the diet-specific subscale of the Stanford Self-efficacy for Diabetes scale, and dietary self-management behaviors using the general diet domain of the Summary of Diabetes Self-Care Activities scale. The primary model was estimated using structural equation modeling in Mplus 7.0 with the robust maximum likelihood estimator (MLR). For inference on the indirect associations, the primary model was re-estimated using maximum likelihood (ML) with 5, 000 bootstrap draws, and bias-corrected 95% confidence intervals were obtained. A covariate-adjusted SEM was further estimated by including sociodemographic and clinical characteristics (age, sex, marital status, education, residence, occupation, income, smoking, disease duration, complications, and hospital). Results Both the primary and dimension-specific SEMs showed good fit. A higher level of health literacy, dietary decisional balance, and dietary self-efficacy was associated with better dietary self-management behaviors. Health literacy showed a significant indirect association with dietary self-management behaviors through dietary self-efficacy ( β = 0.077, 95% CI : 0.017 – 0.137, p = 0.012), but the indirect association through dietary decisional balance was not significant ( β = 0.028, 95% CI : -0.006 – 0.062, p = 0.101). Dimension-specific analyses further showed that communicative health literacy was positively associated with dietary self-efficacy ( β = 0.162, p = 0.034) and dietary self-management behaviors ( β = 0.135, p = 0.043), whereas critical health literacy was positively associated with perceived benefits ( β = 0.332, p < 0.01), and perceived barriers were negatively associated with dietary self-management behaviors ( β = -0.166, p = 0.001). Conclusions and implications Diabetes care should move beyond knowledge transmission by supporting patients’ communicative and critical health literacy, strengthening dietary self-efficacy, and identifying and addressing perceived dietary barriers to support dietary self-management behaviors in patients with T2DM.