Serious adverse events are reported in five (10%) of 52 children, aged 1.5-16 years, treated with the ketogenic diet (4:1 ratio/fat: carbohydrate) over a 22-month period at the Montefiore Medical Center and Albert Einstein College of Medicine, Bronx, NY. The Johns Hopkins KD protocol was followed, and most patients were started at a 4:1 ratio. All patients had intractable epilepsy and had received at least 3 antiepileptic drugs. At diet initiation, 29 were receiving valproate (VPA), of whom 4 developed complications within one month. These included hypoproteinemia, lipemia, hemolytic anemia, and Fanconi’s renal tubular acidosis. Two had severe abnormalities of liver function tests, one with a concomitant thrombocytopenia. 
COMMENT. Using the Johns Hopkins protocol for the ketogenic diet (KD) treatment of childhood refractory epilepsy, serious complications may occur in 10% of patients, often within one month of initiating the diet in a 4:1/ketogenic: antiketogenic ratio. Personally, I have preferred the Mayo Clinic method, which does not usually require the patient’s hospitalization nor an initial period of starvation. The ratio of ketogenic to antiketogenic foods is modified over a 4 day period, beginning with a 1.1:1 ratio on the first day, 1.6:1 on the 2nd, 2.2:1 on the 3rd, and 2.8:1 on the 4th. A 4:1 ratio is rarely required to obtain ketosis and only in older children . With this Mayo method of KD introduction, I have not encountered the adverse reactions reported with the Hopkins protocol. The concomitant use of valproate with the Hopkins ketogenic diet may also be a factor in the incidence of adverse events reported.