Food Diary Completion Does Not Significantly Impact Glycemic Control in an Observational Single-Institution Pilot Study of Patients with Type 2 Diabetes Mellitus.

Abstract

Hemoglobin A1c is frequently used to monitor glycemic control in patients with type 2 diabetes mellitus (T2DM). There is an association between dietary habits and hemoglobin A1c. Food diaries are often used to assist in dietary management and have been associated with modification of dietary habits. We aimed to investigate the impact of completing a seven-day food diary on hemoglobin A1c in subjects with T2DM. We hypothesized that patients who completed a food diary might independently modify their dietary habits, resulting in a clinically significant change in hemoglobin A1c. Forty-five subjects with T2DM who completed a seven-day food diary were included in this observational study. Subjects had a mean hemoglobin A1c at baseline of 7.56 ± 1.43 and a body mass index of 33.6 ± 7.6 kg/m². A majority were female (57.8%) and insulin-dependent (71.1%). The primary outcome of interest was a clinically significant change in hemoglobin A1c (≥0.5%). Outcomes were assessed before and within six months after the food diary completion. Chi-square, independent-sample t-tests, and logistic regression were used to analyze the data. Twelve patients demonstrated a clinically significant decrease in hemoglobin A1c; however, this was not statistically significant regardless of gender (p = 0.5), baseline body mass index (p = 0.5), insulin use (p = 0.3), or community needs index (p = 0.7). Although some patients had clinically significant improvements in their hemoglobin A1c, our findings suggest that the use of food diaries alone without goal-directed initiatives is insufficient to achieve differences in hemoglobin A1c in patients with T2DM and an average A1c within the range of 6%-8%.