Effects of individualized dietary advice compared with conventional dietary advice for adults with type 2 diabetes: a randomized controlled trial

Abstract Background and Aims To investigate the superiority of individualized dietary advice based on dietary assessment for patients with type 2 diabetes. Methods and Results A total of 136 Japanese adults with type 2 diabetes were randomized into either individualized or conventional dietary advice groups after dietary assessment using a self-administered brief-type diet history questionnaire. All participants received three 30-minute face-to-face dietary advice sessions by dietitians at 1, 3, 5 months from study entry. The individualized group received dietary advice based on individual dietary intakes. The conventional group received dietary advice using generalized pamphlets. The primary outcome was the change in HbA1c over 6 months, and secondary outcomes were changes in weight, serum triglyceride, high-density lipoprotein-cholesterol (HDL-C), low-density lipoprotein-cholesterol (LDL-C), and dietary intakes. In total, 126 participants were included in the analysis. After adjustment for age, sex, and baseline measurements, HbA1c significantly decreased larger in the individualized group [−1.1%, 95% CI: −1.3 to −0.8)] than the conventional group [−0.7% (95% CI: −1.0 to −0.4)] (P=0.0495). Weight, serum triglyceride, and LDL-C significantly lowered, and HDL-C significantly increased only in the individualized group, without a significant difference to the conventional group. In dietary changes, the individualized group decreased intakes of energy, confectioneries, meats, oil and fats, and sugar-sweetened beverages. The conventional group decreased alcohol intake, and increased total fat and saturated fatty acid intakes. Conclusions Individualized dietary advice among patients with type 2 diabetes was superior to conventional dietary advice in lowering HbA1c. Trial Registration UMIN000037268 ( https://www.umin.ac.jp/ctr/index.htm ) in July 4, 2019.