Low-Carbohydrate and Ketogenic Dietary Patterns for Type 2 Diabetes Management

Type 2 diabetes mellitus (T2DM) has been traditionally considered a chronic, progressive disease. Since 2017, guidelines from the US Department of Veterans Affairs and US Department of Defense have included low-carbohydrate (LC) dietary patterns in managing T2DM. Recently, carbohydrate reduction, including ketogenic diets, has gained renewed interest in the management and remission of T2DM.

This narrative review examines the evidence behind carbohydrate reduction in T2DM and a practical guide for clinicians starting patients on therapeutic LC diets. We present an illustrative case and provide practical approaches to prescribing a very LC ketogenic (< 50 g), LC (50-100 g), or a moderate LC (101-150 g) dietary plan and discuss adverse effects and management of LC diets. We provide a medication management and deprescription approach and discuss strategies to consider in conjunction with LC diets. As patients adopt LC diets, glycemia improves, and medications are deprescribed, hemoglobin A_1c levels and fasting glucose may drop below the diagnostic threshold for T2DM. Remission of T2DM may occur with LC diets (hemoglobin A_1c < 6.5% for ≥ 3 months without T2DM medications). Finally, we describe barriers and limitations to applying therapeutic carbohydrate reduction in a federal health care system.

The effective use of LC diets with close and intensive lifestyle counseling and a safe approach to medication management and deprescribing can improve glycemic control, reduce the overall need for insulin and medication and provide sustained weight loss. The efficacy and continuation of therapeutic carbohydrate reduction for patients with T2DM appears promising. Further research on LC diets, emerging strategies, and long-term effects on cardiometabolic risk factors, morbidity, and mortality will continue to inform practice.