Association Between the Implementation of Continuous Glucose Monitoring and Changes in Dietary Behavior in Insulin-Treated Patients With Diabetes Regardless of Diabetes Type

BACKGROUND: Diabetic patients receiving insulin therapy require frequent blood glucose monitoring. Recent advancements have enabled constant glucose monitoring using small sensors, such as continuous glucose monitoring (CGM) devices. Several studies have demonstrated improved HbA1c levels following CGM implementation. Glucose monitoring may influence dietary behaviors by providing real-time feedback and visualization of postprandial glucose excursions, which can enhance self-awareness and promote dietary modification. However, few studies have investigated its association with dietary behavioral changes. This study investigated the relationship between CGM implementation and changes in dietary behavior among insulin-using diabetic patients. METHODS: This study was a single-center prospective cohort study. Consecutive adult insulin-using diabetic participants were categorized into CGM and non-CGM groups based on participant intention. The primary outcome was changes in dietary behavior, defined as changes in the percentage of carbohydrates contributing to total caloric intake. Dietary intake was assessed twice at three-month intervals using the Brief-Type Self-Administered Diet History Questionnaire. A difference-in-differences analysis compared changes in carbohydrate intake percentages between the two groups. RESULTS: A total of 42 participants were included. The mean age was 67 ± 13 years, and the median duration of diabetes was 11 (8.0-16.0) years. Thirty-one participants used CGM, whereas 11 did not. At baseline, the mean carbohydrate intake as a percentage of total calories was 51% in the CGM group and 52% in the non-CGM group. After three months, these values were 50% and 56%, respectively. However, difference-in-differences analysis revealed no significant difference between the groups (p = 0.295). Conclusion: CGM implementation was not significantly associated with changes in dietary behavior among insulin-using patients with diabetes. These findings indicate that CGM alone is insufficient, necessitating complementary strategies to promote dietary behavioral modification in this population.