Long-Term Efficacy and Safety of a Low-Carbohydrate Diet in Type 2 Diabetes Remission: A Systematic Review

Type 2 diabetes mellitus (T2DM) is a major global health concern with increasing prevalence and healthcare costs. Despite the availability of pharmacological interventions, sustained glycemic control and disease remission remain challenging. Dietary strategies such as low-carbohydrate diets (LCDs) and ketogenic diets (KDs) are gaining attention for their potential to improve metabolic parameters and induce T2DM remission. The objective of this review is to evaluate the long-term efficacy and safety of low-carbohydrate and ketogenic diets in the management and remission of type 2 diabetes mellitus. The systematic review was conducted following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. PubMed and Cochrane Library databases were searched using predefined keywords and filters. Studies included randomized and non-randomized clinical trials published in English within the last 24 years. Eligible studies involved adult T2DM patients on LCDs/KDs with a follow-up period of at least 12 months. The primary outcomes were T2DM remission, changes in glycated hemoglobin (HbA1c), body weight, body mass index (BMI), and secondary outcomes included blood pressure, lipid profiles, and adverse effects. Out of 124 initially identified studies, six studies met the inclusion criteria, with follow-up durations ranging from one to eight years. Low-carbohydrate and ketogenic diets led to significant reductions in HbA1c, body weight, BMI, and systolic blood pressure. In terms of long-term studies, remission rates were highest at one year (up to 62%) and declined to 13% by year five. Participants in the intervention groups also experienced reduced dependency on glucose-lowering and antihypertensive medications. Despite some weight regain and glycemic relapse over time, the overall metabolic improvements suggest a beneficial role of dietary intervention in T2DM management. Low-carbohydrate and ketogenic diets appear to be effective in improving metabolic outcomes and inducing remission in T2DM. These dietary interventions may serve as viable alternatives to pharmacological treatments or bariatric surgery, provided that long-term adherence and support mechanisms are in place. Further research is needed to address long-term safety, sustainability, and individualized dietary approaches.