Lifestyle behaviors that reduce food and fat intake in patients with type 2 diabetes within 3 months of diagnosis lead to a reduction in the HbA1c level after 12 months.

It is important to provide "Diabetes Self-Management Education and Support," the ongoing process of facilitating the knowledge, skills, and ability necessary for diabetes self-care, immediately after diagnosis. In this 12-month (12 M) longitudinal observational study, outpatients within 3 months of their first diagnosis of type 2 diabetes mellitus (T2DM) were surveyed at baseline (BL) and 12 M using a self-administered questionnaire used in the "Lifestyle Intervention Support Software for Diabetes Prevention" and medical record survey. To explore factors associated with the change extent in HbA1c level during the 12 M post-diagnosis, hierarchical multiple regression analysis was performed with sex, age, HbA1c level at BL, medication in the first 12 M post-diagnosis, and lifestyle behaviors related to diet and exercise therapy as independent variables. The HbA1c level of the 89 participants was 8.4% ± 2.2% at BL and 6.7% ± 1.0% at 12 M. "ND06 I add milk to coffee or tea (reverse item)" (β = -0.110, p = 0.015), "RD15 I eat vegetable dishes such as a vegetable side dish and/or a vinegar or pickle dish" (β = 0.151, p = 0.003), "ND02 I eat until I feel full (reverse item)" (β = -0.115, p = 0.024), and "RD14 I select udon or soba instead of Chinese noodles in soups" (β = -0.113, p = 0.007) were associated with the change extent in the HbA1c level during the 12 M post-diagnosis. Overall, it may be useful to support patients with T2DM early post-diagnosis to improve lifestyle behaviors associated with the extent of change in HbA1c level during the 12 M post-diagnosis.