The efficacy of low-carbohydrate diets on glycemic control in type 2 diabetes: a comprehensive overview of meta-analyses of controlled clinical trials

This umbrella meta-analysis comprehensively evaluates the effectiveness of low-carbohydrate diets (LCDs) in managing glycemic control among individuals with type 2 diabetes mellitus (T2DM). Following PRISMA guidelines and registered in the PROSPERO database for transparency, a thorough literature search was conducted across key databases, including EMBASE, Scopus, and PubMed. The review focuses on randomized controlled trials (RCTs) targeting adults with T2DM, with methodological quality assessed using the AMSTAR2 tool. The findings reveal that LCDs resulted in significant reductions in hemoglobin A1c (HbA1c) levels in 16 out of 21 studies, indicating substantial short-term improvements in glycemic control. However, four studies reported no significant changes, highlighting individual variability in responses. While some studies showed reductions in fasting blood glucose, results were inconclusive overall. Insulin sensitivity improved during the short term, but these benefits were not sustained over the long term. Overall, the analysis suggests that LCDs provide considerable short-term glycemic control benefits for T2DM patients, alongside potential long-term advantages. Further research is necessary to develop personalized dietary strategies that address the diverse needs of different populations, ultimately enhancing the effectiveness of diabetes management.