Lessons learned from recent clinical trials of ketogenic diet therapies in adults.

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.