Nutritional Counseling Is Independently Associated with Greater Knowledge of Drug-Food Interactions in Patients with Type 2 Diabetes.

Background

Type 2 diabetes mellitus (T2DM) is commonly managed with complex pharmacotherapy combined with dietary modification, which increases the risk of clinically relevant drug-food interactions (DFIs). Despite their potential impact on treatment efficacy and safety, patient knowledge of DFIs-particularly in the context of modern therapies such as glucagon-like peptide-1 receptor agonists (GLP-1 RAs)-remains insufficiently explored.

Methods

This cross-sectional study assessed knowledge of DFIs among 103 adults with T2DM using a self-administered, expert-validated questionnaire. Data on sociodemographic characteristics, clinical variables, anti-diabetic therapy (including GLP-1 RAs), sources of education, and attendance at dietary consultations were collected. Knowledge scores were calculated based on correct responses and categorized into tertiles (low, moderate, high). Associations were analyzed using non-parametric tests. Multivariable logistic regression was performed to identify independent predictors of moderate-to-high DFI knowledge.

Results

Substantial gaps in DFI knowledge were identified, particularly regarding interactions involving dietary fiber, dairy products, grapefruit juice, and nutrient deficiencies associated with long-term pharmacotherapy. Knowledge level was not significantly associated with age, educational attainment, diabetes duration, or GLP-1 RA use. Female sex was associated with higher knowledge in univariate analysis (p = 0.026); however, this association did not remain significant in the multivariable regression model. Attendance at at least one dietary consultation in the previous year was significantly associated with higher knowledge levels (p = 0.041) and remained an independent predictor in multivariable analysis (OR = 2.31; 95% CI: 1.04-5.15; p = 0.039). Most participants reported not receiving prior education on DFIs, while expressing a strong need for more frequent counseling.

Conclusions

Patients with T2DM demonstrate insufficient knowledge of clinically relevant DFIs, including selected issues related to GLP-1 RA therapy. Attendance at structured dietary consultations was independently associated with higher levels of DFI knowledge; however, the directionality and causality of this relationship cannot be established. Given the cross-sectional design and the assessment of knowledge rather than behavioral or clinical outcomes, these findings should be interpreted as hypothesis-generating. Further longitudinal and interventional studies are required to determine whether improved DFI knowledge translates into meaningful changes in dietary behavior, treatment adherence, or metabolic outcomes.