Description
The ketogenic diet is designed to establish and maintain ketosis. The diet is very high in fat and severely restricted in carbohydrates. This is done by calculating the diet to provide 3 to 4 grams of fat for each 1 gram of protein and carbohydrate combined, thus converting the fuel burned by the body from carbohydrate to fat. A physician prescribes the ratio of 3:1 or 4:1 as appropriate for each individual patient. The diet is calculated to meet the specific needs of each individual for calories and protein, and provides little to no carbohydrate depending on protein requirements. Even with the high fat content of the diet, weight is usually maintained with very little gain. This is possible because calories are calculated to meet only 75% of the individual’s Dietary Reference Intake (DRI) for energy. The foundation of the diet is either heavy whipping cream or MCT oil. The diet using whipping cream is described below.
Indications
The diet serves as an adjunct to anti-convulsant medications in controlling intractable seizures. It is used in cases of resistance to medications or drug toxicity (1,2). Sustained ketosis appears to be important in modifying the convulsive threshold (1,3). The diet seems to be most effective in children 18 months to 10 years of age (4), although it can be used with older children and adults with varying degrees of success. The diet is administered to those who have myoclonic absence (drop) and atonic seizures, which are difficult to control with medications. It may also benefit children with generalized tonic-clonic (grand mal) seizures and seizures of the Lennox-Gestault Syndrome. The ketogenic diet can be used for all types of seizures, especially if medication therapy is not effective (5).
The diet requires a trial period of 2 to 3 months during which effectiveness is assessed and the diet is adjusted to maintain strong ketosis. Once it is determined that the diet is effective on controlling seizure activity, a commitment of 1 to 2 years is required after which weaning is done gradually. Because of the extreme dietary regimens involved in this diet, the Johns Hopkins Pediatric Epilepsy Center recommends use of the ketogenic diet for those individuals who have more than 2 seizures a week despite treatment with at least 2 different anticonvulsant medications (6).
Nutritional Adequacy
The ketogenic diet is inadequate in vitamin B-complex vitamins, folate, iron, calcium, and zinc. The diet must be supplemented with vitamins, iron and calcium in forms that are sugar-free.
How to Order the Diet
Order as “Ketogenic Diet.” A nutrition consult by a registered dietitian must accompany the diet order, as the diet has to be precisely calculated. All medications must be carbohydrate free, as well as toothpaste. The diet must be initiated in a hospitalized setting under close supervision.
Planning the Diet
A gram scale and a copy of the Epilepsy Diet Treatment book (6) are paramount in administering this diet effectively
