A total of 374 million adults worldwide are living with prediabetes. Medical nutrition therapy provided by a registered dietitian nutritionist, such as that for lifestyle interventions, has the potential to improve glycemic control and prevent the progression to Type 2 diabetes mellitus, or T2DM.
A systematic review was completed with the goal of examining the effectiveness of MNT provided by an RDN — compared with standard care — on glycemic, cardiometabolic and anthropometric outcomes in adults with prediabetes. Searches were conducted for randomized controlled trials published between 1995 and 2022. The certainty of evidence was assessed for each outcome using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) method.
Thirteen randomized controlled trials were included in the analysis, showcasing a variety of MNT interventions delivered by RDNs. Intervention durations ranged from 3 to 24 months.
Compared with standard care, MNT improved hemoglobin A1c (HbA1c) (mean difference [95% confidence interval]: -0.30% [-0.49, -0.12]) and fasting blood glucose (-4.97 mg/dL [-6.24, -3.71]). Statistically significant improvements were found in anthropometrics (weight, body mass index and waist circumference), cholesterol (total, high- and low-density lipoproteins), and blood pressure (systolic and diastolic). No significant effect was found on T2DM incidence or triglyceride concentrations.
The certainty of evidence was moderate for fasting blood glucose and low for HbA1c and incidence of T2DM. In adults with prediabetes, MNT was effective in improving glycemic outcomes, anthropometrics, blood pressure and most lipid levels. However, most studies had a risk of bias because of the randomization process or deviations from intended interventions. In conclusion, this systematic review found that MNT plays a key role in improving cardiometabolic risk factors in adults with prediabetes.
Read the full article, "The effectiveness of medical nutrition therapy provided by a dietitian in adults with prediabetes: a systematic review and meta-analysis," published in The American Journal of Clinical Nutrition. View the Diabetes: Prevention of Type 2 Project on the Academy's Evidence Analysis Library to learn more.
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