BACKGROUND: Identification of dietary patterns is important for glycemic management in elderly patients with type 2 diabetes mellitus (T2DM). METHODS: Elderly T2DM patients (> 65 years of age, n = 48) were categorized based on their concentration of glycated hemoglobin (HbA1c). Subjects with HbA1c levels below 7% were placed in the good control (GC) group and those with HbA1c levels equal to or above 8% were placed in the poor control (PC) group. Anthropometric data, blood parameters, and dietary intake records were compared between the groups. Statistical analysis included Student's t-test, chi-square test, and Pearson correlation coefficient test. RESULTS: Anthropometric data, including body mass index (24.7 +/- 2.9 kg/m2), did not differ between the GC and PC groups. Significant abnormalities in blood glucose levels (P < 0.01), lean body mass (P < 0.01), and plasma protein and albumin levels (P < 0.05, P < 0.01) were found in the PC group. In contrast to the GC group, the PC group depended on carbohydrate (P = 0.014) rather than protein (P = 0.013) or fat (P = 0.005) as a major source of energy, and had a lower index of nutritional quality for nutrients such as protein (P = 0.001), and all vitamins and minerals (P < 0.001, 0.01, or 0.05 for individual nutrients), except vitamin C, in their usual diet. Negative correlations between HbA1C levels and protein (r = -0.338, P < 0.05) or fat (r = -0.385, P < 0.01) intakes were also found. CONCLUSIONS: Healthcare professionals should encourage elderly diabetic patients to consume a balanced diet to maintain good glycemic control.