Effects of 12 Nutritional Interventions on Type 2 diabetes：A Systematic Review with Network Meta-Analysis of Randomized Trials Short Running Title: Effectiveness of 12 Diets in T2DM Management

Background Numerous trials confirm dietary interventions benefit type 2 diabetes mellitus (T2DM) management, but the optimal model is unclear. We evaluated 12 interventions through a Network Meta-Analysis (NMA) on their effects on Fasting Plasma Glucose (FPG), 2-hour Postprandial Glucose (2hPG), HbA1c, HOMA-IR, Total Cholesterol (TC), Triglycerides (TG), and BMI, providing evidence to guide clinical nursing. Methods We conducted an NMA of RCTs (Prospero registration: CRD42023429616) examining dietary interventions for T2DM, searching databases from January 1, 2010, to August 31, 2024. Two reviewers independently screened studies, extracted data, and assessed bias using the Cochrane Risk of Bias tool. Key and important outcomes were analyzed using Stata 17.0, with evidence quality assessed via GRADE and CINeMA. Results Our initial search identified 301,997 articles; 18 RCTs involving 1,687 patients met our criteria. Twelve dietary interventions, including MNT, digital models, and LGI + LGL diets, were analyzed. Superior glycemic control was observed in some diets according to SUCRA (P < 0.05), with outcomes ranging from moderate to high quality. Conclusions MNT, LGI diets, and digital models show efficacy in improving key T2DM metrics. LGI + LGL diets potentially reduce TC, TG, and BMI, while low GI diets best improve HOMA-IR. These results support the effectiveness of these interventions, though further large-scale, multi-center RCTs are needed to confirm long-term safety and effects. Trial registration CRD42023429616