Cross-sectional association of irregular dietary habits with glycemic control and body mass index among people with diabetes.

Aims/introduction: To determine the association of irregular dietary habits with HbA1c and body mass index (BMI) in people with diabetes.

Materials and methods: We included 4,421 people with diabetes aged 20-74 years (type 1 diabetes (T1D), 19.1%) who answered a questionnaire at mealtime. Adjusted least square means in HbA1c and BMI in patients with irregular dietary habits: "irregular mealtimes (irregular)," "skipping breakfast (SB)," and "late dinner (LD)" were compared to those with "regular dietary habits (regular)." Multivariable logistic regression analyses were performed to examine the association of irregular dietary habits with HbA1c ≥ 7% and BMI ≥25 kg/m².

Results: HbA1c was significantly higher for "irregular" in both sexes and for "LD" in women than those of "regular" in people with T1D. HbA1c was significantly higher for "LD," and BMI was higher for almost all irregular dietary habits than those of "regular" in people with type 2 diabetes (T2D). Odds ratios (ORs) for HbA1c ≥7% were 3.20 (95% confidence interval (CI), 1.30-7.89) for T1D women with "irregular" and 1.73 (1.20-2.49) and 2.20 (1.14-3.65) for T2D men and women with "LD," respectively. ORs for BMI ≥25 kg/m² were 1.60 (95% CI, 1.15-2.22) for T2D men with "irregular" and 1.43 (1.02-2.01) and 2.11 (1.21-3.65) for T2D women and men with "LD," respectively.

Conclusions: Irregular mealtimes are associated with poor glycemic control in T1D women and are associated with obesity in T2D men. Furthermore, a late dinner was associated with high HbA1c levels and BMI in people with T2D.