The current review highlights the evidence supporting the use of ketogenic diet therapies in the management of adult epilepsy, adult malignant glioma and Alzheimer’s disease. An overview of the scientific literature, both preclinical and clinical, in each area is presented and management strategies for addressing adverse effects and compliance are discussed.

Ketogenic diet therapies are high-fat, low-carbohydrate diets designed to mimic a fasting state. Although initially developed nearly one century ago for seizure management, most clinical trials for the management of drug-resistant epilepsy in children as well as adults have been conducted over the last 3 decades. Moreover, ketogenic diets offer promising new adjunctive strategies in the critical care setting for the resolution of acute status epilepticus when traditional antiseizure drugs and anesthetic agents fail. Here, we review the history of ketogenic diet development, the clinical evidence supporting its use for the treatment of drug-resistant epilepsy in children and adults, and the early evidence supporting ketogenic diet feasibility, safety, and potential efficacy in the management of status epilepticus.

Purpose of review Although ketogenic diet therapies (KDTs) were first developed as a treatment for patients with epilepsy, their potential efficacy for a broader number of neurologic and nonneurologic disorders and conditions has been explored over the last 10–20 years. The most recent clinical trials of KDTs in adults have highlighted common methodological aspects that can either facilitate or thwart appropriate risk/benefit analyses, comparisons across studies, and reproducibility of findings in future studies. Recent findings Recent evidence suggests that KDTs not only improve seizure control, but also improve other neurologic conditions, including nonmotor Parkinson's disease symptoms. Therapies targeting nutritional ketosis without comprehensive diet modification improve cognition and cerebral blood flow in Alzheimer's disease patients. KDTs lower hemoglobin A1c levels and diabetes medication use in patients with Type 2 diabetes and mixed results have been observed when used for performance enhancement in athletes and healthy volunteers. Summary Clinical studies of KDTs show promise for a variety of clinical indications. Future studies should factor in high potential participant attrition rates and utilize consistent and standard reporting of diet type(s), compliance measures, and side-effects to enable the reproducibility and generalizability of study outcomes.