A Nutritional Strategy Based on Multiple Components for Glycemic Control in Type 2 Diabetes: A Multicenter Randomized Controlled Clinical Trial

Background/objectives: The optimal dietary approach for managing glycemic and metabolic control in type 2 diabetes (T2D) is still uncertain, though it should be tailored for clinical settings. Therefore, we sought to assess the impact of a multicomponent nutritional strategy on glycemic control in T2D patients within a public health system.

Methods: NUGLIC was an open-label, parallel-group, superiority, multicenter randomized controlled trial. Participants aged 30 and older with poorly controlled T2D were randomly assigned to either (1) a personalized dietary prescription (control group, n = 185) or (2) a strategy involving targeted nutritional advising, mindfulness techniques, and short message services (NUGLIC [intervention] group, n = 186). The primary outcomes were glycated hemoglobin (HbA1c, %) measured after 24 weeks and glycemic control, defined as having an HbA1c > 7% at baseline and achieving ≤7% after follow-up, or having HbA1c ≤ 7% at baseline and reducing the use of glucose-lowering medications post-follow-up. The secondary outcomes included cardiometabolic features, self-care practices, diet quality, and quality of life.

Results: A total of 371 participants were included in an intention-to-treat analysis for the primary outcomes. At six months, both groups exhibited a reduction in HbA1c levels compared to the baseline (NUGLIC group: -0.6% [95% confidence interval (CI) -0.9; -0.3], p < 0.001; control group: -0.5% [95% CI -0.7; -0.3], p < 0.001). However, no significant differences were observed between the groups in terms of HbA1c after follow-up (intervention group: 8.1%; control group: 8.3%; difference: -0.2% [95% CI -0.5; 0.1], p = 0.30) or glycemic control (NUGLIC group: 19.9%; control group: 18.9%; odds ratio 0.96 [95% CI 0.56; 1.67], p = 0.89). While the control group showed an improvement in overall diet quality, no significant differences emerged between the groups by the end of this study (p = 0.13). There were also no significant differences in other secondary outcomes nor in the use of glucose-lowering medications and adverse events after follow-up.

Conclusions: The multicomponent nutritional strategy did not demonstrate superiority over personalized dietary prescriptions in achieving glycemic control for participants with poorly managed T2D. In this sense, both nutritional interventions could be used in clinical practice to improve HbA1c levels, considering the profile and preferences of individuals.