Ketogenic Diet

Description

The ketogenic diet is a high-fat, adequate-protein, low-carbohydrate diet used to control refractory epilepsy. Although it is unclear exactly how the diet works to control seizures, the child enters a state of ketosis while on the diet and uses ketones as an energy source instead of glucose. The diet is quite restrictive; even small amounts of carbohydrate can stop the ketosis and lead to a breakthrough seizure. Ketogenic diets are usually used as secondary therapy after first-line medications fail.

Effects and Risks

With the diet, approximately 1/5-1/3 of patients experience a 90% seizure reduction [Keene: 2006], 1/3 experience a 50-90% seizure reduction, and 1/3 either have no improvement or are unable to maintain the diet. Side effects and risks of the diet include: [Groesbeck: 2006]
Nausea/vomiting Growth failure
Constipation Kidney stones
High cholesterol (which may be reversed
when the diet is stopped)
Osteoporosis
Hypoproteinemia Impaired immune response
Disturbances in liver function Abnormal heart rhythms
Hemolytic anemia Death

Selection of Patients

Most physicians will recommend the ketogenic diet only after the patient has not achieved seizure control on antiepileptic medication. The diet is very rigorous and needs patient, family, and school cooperation. There must be some assurance that patients will not "cheat" either because they are unable to feed themselves due to youth or disability or because they do not understand the goals of the diet. Children with some specific metabolic disorders, especially those involving the fat metabolism system, should not be put on the ketogenic diet. [Kossoff: 2018] Children who are developmentally unable to comprehend the needs of the diet but who are mobile and able to feed themselves are not good candidates as it is impossible to control their behavior over the long term.
In 1 study, infants with intractable epilepsy responded well to the diet and the diet was well tolerated. [Wirrell: 2018] The ketogenic diet should be considered early on in children with glucose transporter 1 deficiency, infantile spasms, tuberous sclerosis complex, Dravet syndrome, and possibly other conditions. [Kossoff: 2018]

Ketogenic Diet Initiation

After receiving diet initiation education, patients fast after eating dinner the night before they enter the hospital. Upon arrival at the hospital, intense training regarding the diet is begun and monitoring of the patient for blood glucose, hydration, and ketosis is started. Baseline studies such as EEG, EKG, and metabolic laboratory testing may be performed. The fast is continued until ketosis is achieved (usually 1-2 days), and then a reduced-calorie ketogenic diet is started. Calories are gradually increased over the next few meals to the full caloric requirement, as calculated by the nutritionist, to provide a ratio of (fats):(carbohydrates) of 3-4:1.
Careful monitoring and education continue until the family is comfortable with the diet. Frequent follow-ups with the pediatric neurologist are necessary over the first weeks and months after discharge. Families continue to serve the ketogenic diet meals and monitor urine ketones and seizure frequency. Over-the-counter and prescription medications, as well as vitamins, need to be included in the daily diet plan since they may contain carbohydrates. Antiepileptic medications, which will be continued at first, will be adjusted as necessary for the diet and the number of seizures. Depakote and topiramate, especially, need careful monitoring while the child is on these medications and the diet.
The diet must be carefully calculated each day for the prescribed ratio of fat to protein plus carbohydrate. Adherence and adequacy of the diet are measured with urine dipsticks for ketones. A modified Atkins diet has also been tried and may be helpful in the control of intractable seizures. [Kang: 2007] [Kossoff: 2008]

Discontinuing the Diet

Unless medical side effects intervene, patients and families should stick to the diet for 2 months before deciding on its efficacy. After a decision has been made to stop the diet, the child is weaned off it gradually. Common reasons to discontinue the diet include a less than desirable seizure reduction, side effects, and the limited diet options. [Henderson: 2006]

Resources

Information & Support

For Parents and Patients

Ketogenic Diet (Epilepsy Foundation)
Information about the diet (how to begin, what it is like, when to stop), side effects, and medication changes that may be needed.

Ketogenic Dietary Therapies (Matthew's Friends)
Extensive information about ketogenic therapy, recipes, community, and events.

Ketogenic Therapy (Charlie Foundation)
Information about ketosis, the ketogenic diet, recipes, and support.

Practice Guidelines

Kossoff EH, Zupec-Kania BA, Auvin S, Ballaban-Gil KR, Christina Bergqvist AG, Blackford R, Buchhalter JR, Caraballo RH, Cross JH, Dahlin MG, Donner EJ, Guzel O, Jehle RS, Klepper J, Kang HC, Lambrechts DA, Liu YMC, Nathan JK, Nordli DR Jr, Pfeifer HH, Rho JM, Scheffer IE, Sharma S, Stafstrom CE, Thiele EA, Turner Z, Vaccarezza MM, van der Louw EJTM, Veggiotti P, Wheless JW, Wirrell EC.
Optimal clinical management of children receiving dietary therapies for epilepsy: Updated recommendations of the International Ketogenic Diet Study Group.
Epilepsia Open. 2018;3(2):175-192. PubMed abstract / Full Text

Helpful Articles

Zupec-Kania B, Zupanc ML.
Long-term management of the ketogenic diet: seizure monitoring, nutrition, and supplementation.
Epilepsia. 2008;49 Suppl 8:23-6. PubMed abstract

Zupec-Kania BA, Spellman E.
An overview of the ketogenic diet for pediatric epilepsy.
Nutr Clin Pract. 2008;23(6):589-96. PubMed abstract

Kossoff EH, Dorward JL.
The modified Atkins diet.
Epilepsia. 2008;49 Suppl 8:37-41. PubMed abstract

Authors & Reviewers

Last update/revision: January 2019
Current Authors and Reviewers:
Author: Lynne M. Kerr, MD, PhD
Authoring history
2011: first version: Lynne M. Kerr, MD, PhDA
AAuthor; CAContributing Author; SASenior Author; RReviewer

Page Bibliography

Groesbeck DK, Bluml RM, Kossoff EH.
Long-term use of the ketogenic diet in the treatment of epilepsy.
Dev Med Child Neurol. 2006;48(12):978-81. PubMed abstract

Henderson CB, Filloux FM, Alder SC, Lyon JL, Caplin DA.
Efficacy of the ketogenic diet as a treatment option for epilepsy: meta-analysis.
J Child Neurol. 2006;21(3):193-8. PubMed abstract

Kang HC, Lee HS, You SJ, Kang du C, Ko TS, Kim HD.
Use of a modified Atkins diet in intractable childhood epilepsy.
Epilepsia. 2007;48(1):182-6. PubMed abstract

Keene DL.
A systematic review of the use of the ketogenic diet in childhood epilepsy.
Pediatr Neurol. 2006;35(1):1-5. PubMed abstract

Kossoff EH, Dorward JL.
The modified Atkins diet.
Epilepsia. 2008;49 Suppl 8:37-41. PubMed abstract

Kossoff EH, Zupec-Kania BA, Auvin S, Ballaban-Gil KR, Christina Bergqvist AG, Blackford R, Buchhalter JR, Caraballo RH, Cross JH, Dahlin MG, Donner EJ, Guzel O, Jehle RS, Klepper J, Kang HC, Lambrechts DA, Liu YMC, Nathan JK, Nordli DR Jr, Pfeifer HH, Rho JM, Scheffer IE, Sharma S, Stafstrom CE, Thiele EA, Turner Z, Vaccarezza MM, van der Louw EJTM, Veggiotti P, Wheless JW, Wirrell EC.
Optimal clinical management of children receiving dietary therapies for epilepsy: Updated recommendations of the International Ketogenic Diet Study Group.
Epilepsia Open. 2018;3(2):175-192. PubMed abstract / Full Text

Wirrell E, Eckert S, Wong-Kisiel L, Payne E, Nickels K.
Ketogenic Diet Therapy in Infants: Efficacy and Tolerability.
Pediatr Neurol. 2018;82:13-18. PubMed abstract