Effects of different dietary patterns on glucose management in type 1 diabetes: a systematic review and meta-analysis of randomized controlled trials.

Background: Effective glucose management is essential to prevent complications in type 1 diabetes. While nutrition therapy is crucial, the optimal diet remains uncertain. Our systematic review and meta-analysis synthesized evidence from randomized controlled trials (RCTs) on the impact of various diets on glucose management in type 1 diabetes. Methods: We systematically searched Medline, Embase, and Cochrane Library up to 11 November 2024 for RCTs on dietary patterns and glucose control outcomes in type 1 diabetes, including HbA1c, time in range (TIR), coefficient of variation (CV), hypoglycemia, insulin dose, and anthropometric characteristics. Two reviewers independently extracted data and assessed the risk of bias using the RoB-2 tool. We estimated summary mean differences (MD) with 95% CIs using random-effects models. The certainty of the evidence was evaluated using GRADE. The study protocol was registered in PROSPERO (CRD42023479252). Findings: Out of 5287 studies, 35 RCTs involving children, adolescents, and adults with type 1 diabetes were eligible. Higher-fiber diets (≥35 g/day, 5 RCTs) reduced HbA1c (MD -0.46%, 95% CI -0.93 to 0.00, I Interpretation: Maintaining a high-fiber diet while restricting other carbohydrates may improve glycemic control in individuals with type 1 diabetes. Further investigation is needed into long-term effects and other diets. Funding: Swedish Research Council, Swedish Diabetes Foundation, and the Strategic Research Programme in Diabetes at Karolinska Institutet.