Effectiveness of an adapted diabetes nutrition education program on clinical status, dietary behaviors and behavior mediators in adults with type 2 diabetes: a randomized controlled trial.

Purpose: This study evaluated the effectiveness of an adapted social-cognitive theory underpinned diabetes nutrition education program (NEP) on: clinical (HbA1c, BMI, blood lipids, blood pressure) and selected dietary behaviors (starchy foods and energy intake, vegetables and fruit intake) and behavior mediators (knowledge and diabetes management self-efficacy) in patients with type 2 diabetes mellitus (T2DM).

Methods: A tertiary hospital outpatient adults (40-70 years) with poorly controlled (HbA1c ≥ 8 %) T2DM were randomized to either intervention group (: NEP, 7-monthly group education sessions, bi-monthly follow-up sessions, 15-minute individual session, workbook + education materials) or control group (: education materials only). NEP aimed to improve clinical status through improved dietary behaviors and behavior mediators. Outcomes and changes in diabetes medication were assessed at six and 12 months. Intention-to-treat analysis was conducted. ANCOVA compared the groups (baseline values, age, sex adjustments).

Results: Forty-eight (62.3 %) participants completed the study. Intervention group compared to the control group had lower (-0.53 %), clinically meaningful HbA1c (primary outcome) at 6 months, albeit not sustained at 12 months. Compared to the control group, the intervention group had significantly lower: (i) systolic blood pressure at six and 12 months (ii) diastolic pressure at 12 months, (iii) energy intake at six-months, (iv) up-titration of insulin at six and 12 months and higher diabetes knowledge scores at six months.

Conclusions: NEP had limited effects on HbA1c, targeted dietary behaviors and behavior mediators but showed positive effects on blood pressure. The NEP health cost savings potential supports the need for improving program participation.

Trial Registration: ClinicalTrials.gov. number NCT03334773; 7 November 2017 retrospectively registered.