Efficacy of long‐term low carbohydrate diets for patients with type 2 diabetes: A systematic review and meta‐analysis

AIMS/INTRODUCTION: Efficacy of long-term low-carbohydrate diets (LCD) to improve glycemic management for type 2 diabetes remains controversial. Thus, we investigated the association between long-term LCD and glycemic control in individuals with type 2 diabetes. MATERIALS AND METHODS: We searched PubMed, Embase and the Cochrane Database for articles published up to June 2023, and included randomized controlled trials conducted on LCD interventions for >12 months in adults with type 2 diabetes. Primary outcome was the difference in glycated hemoglobin between long-term LCD and control groups. Additionally, we evaluated the differences in changes in systolic and diastolic blood pressure, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglyceride, and weight between long-term LCD and control groups. RESULTS: Six studies were identified and met the inclusion criteria. This study did not show significant differences in changes in glycated hemoglobin between long-term LCD and control diets (standardized mean difference -0.11, 95% confidence interval -0.33 to 0.11, P = 0.32). As with glycemic control, there were no significant differences in the changes in weight loss, blood pressure, and low-density lipoprotein cholesterol between long-term LCD and control diets. However, long-term LCD were associated with greater elevation in high-density lipoprotein cholesterol (standardized mean difference 0.22, 95% confidence interval 0.04-0.41; P = 0.02) and decrease in triglyceride (standardized mean difference -0.19; 95% confidence interval -0.37 to 0.02; P = 0.03) than that in control diets. CONCLUSIONS: Our findings suggest efficacy of long-term LCD in treating dyslipidemia in individuals with type 2 diabetes, but do not recommend long-term LCD for glycemic control in the individuals.