(P28-006-23) Dietary Self-Monitoring Trajectories and Associations With Glycemic Control in Adults With Prediabetes and Moderately-Controlled Type 2 Diabetes

Objectives: This secondary analysis aimed to describe distinct patterns of dietary self-monitoring adherence in adults with prediabetes and moderately controlled type 2 diabetes and examine whether adherence patterns were longitudinally associated with changes in glycemic control.

Methods: We analyzed data from participants who completed the Personal Diet Study, a 6-month behavioral weight loss trial. All participants received behavioral counseling and were instructed to enter daily dietary intake into a smartphone app (self-monitoring period 5.3 ± 0.03 months). Dietary data were collected from the app, and monthly dietary self-monitoring adherence was calculated as the percentage of days that participants logged at least 50% of their daily caloric goal. Mean amplitude of glycemic excursions (MAGE), a measure of glycemic variability collected from blinded continuous glucose monitoring, and hemoglobin A1c (HbA1c) were assessed at baseline, 3 months, and 6 months.

Group-based trajectory modeling was used to identify distinct patterns of dietary self-monitoring adherence over the self-monitoring period. Using linear mixed models, we examined changes in MAGE and HbA1c between trajectory groups from baseline to 6 months.

Results: The analytic sample included 171 participants (58.9 ± 10.8 years; 65.5% female; 55.0% White; 24.3% Black; BMI: 33.7 ± 4.8 kg/m²; 21.1% using metformin at baseline). Three distinct patterns of dietary self-monitoring adherence were identified: consistently high, with average adherence rates changing from 89.0% to 74.5% over the self-monitoring period (n=55; 32.2%); high to low, with average adherence rates changing from 63.8% to 15.4% (n=44; 25.7%); and consistently low, with average adherence rates changing from 16.6% to 1.4% (n=72; 42.1%). At 6-months, the consistently high trajectory was associated with greater decreases in MAGE (β: -7.83 mg/dL; 95% CI: -13.95, -1.70; p=0.012) and HbA1c (β: -0.18%; 95% CI: -0.33, -0.04; p=0.015) compared to the consistently low trajectory.

Conclusions: In adults with prediabetes and moderately controlled type 2 diabetes participating in a behavioral weight loss intervention, greater adherence to dietary self-monitoring contributed to improvements in glycemic control.

Funding Sources: American Heart Association 17SFRN33590133