Background: A diet that is high in fat and low in carbohydrates (ketogenic diet) has long been used to treat intractable seizures in children. The diet fell out of favor with the advent of new antiepileptic medications and because of perceived problems with adherence. The effectiveness of the diet was then demonstrated in a study of 150 children with seizures inadequately controlled by medications. Of these children, 7 percent were seizure free and 20 percent had an almost complete reduction of their seizures at 12 months. In general, about one half of the children on a ketogenic diet benefit, whereas the other children do not benefit or are unable to maintain the diet.

Recommendations: Various modifications of the diet exist, including a medium-chain triglyceride variation with greater carbohydrate allowance than the classic long-chain triglyceride diet. A modified Atkins diet is an acceptable alternative, as is a low-glycemic index diet with restriction of fruits, breads, and starches. Candidates for the diet include children of various ages who have any type of seizure, whether generalized or partial. Adverse effects include transient acidosis, hypoglycemia, gastrointestinal problems, dehydration, and lethargy when the diet is initiated. In the long term, the diet can cause abnormal lipid profiles, kidney stones, and growth delays. Calcium supplementation has not been proven to prevent loss of bone density or lower the risk of skeletal fractures. As shown by preliminary studies, the ketogenic diet may be beneficial in the modification and treatment of other illnesses, particularly neurodegenerative disorders (see accompanying table).