Ketogenic diet in the treatment of epilepsy

Ryan W Y Lee MD (

Dr. Lee of the John A Burns School of Medicine at the University of Hawaii has no relevant financial relationships to disclose.

Miki Wong MACO RDN (Ms. Wong of Shriners Hospitals for Children–Honolulu has no relevant financial relationships to disclose.)
Barry Wolf MD PhD, editor. (Dr. Wolf of Lurie Children's Hospital of Chicago has no relevant financial relationships to disclose.)
Originally released July 15, 1999; last updated February 18, 2020; February 18, 2023

Key points


• The ketogenic diet is a medical treatment for intractable epilepsy and should only be administered under direct medical supervision.


• The ketogenic diet is an effective treatment for seizures that are refractory to antiepileptic drugs. It has been used as an earlier treatment option for infantile spasms, with some promising results.


• The ketogenic diet serves as an effective treatment option regardless of seizure type, seizure syndrome, and age.


• If a patient has some improvement in seizures on the ketogenic diet, but still continues to have seizures, fine-tuning the diet by adjusting the calories or the ratio may provide additional seizure control.


• The ketogenic diet is not considered a “healthy” or “all-natural” therapy for seizures. The diet is very restrictive and does not provide adequate vitamins and nutrients for optimal growth. Thus, all patients on the ketogenic diet are required to take daily vitamin and mineral supplements in order to maintain optimal nutrition.


• The ketogenic diet does have potential side effects, as do all treatment options for seizures. The most common side effects associated with starting the diet include nausea and vomiting. The most common side effects associated with long-term therapy on the diet include constipation and reflux. The risk of kidney stones is increased in individuals on the ketogenic diet.


• The modified Atkins diet is a newer, more liberal version of the ketogenic diet that has shown promising results, especially for teenagers and adults interested in trying a diet therapy option. The modified Atkins diet does not restrict calories, protein, or fluids, but does encourage a high-fat diet while limiting the total daily grams of carbohydrate.


• The low glycemic index treatment diet allows for a higher content of carbohydrates by limiting the carbohydrate sources to those that have a glycemic index of 50 and below. It also allows for higher content of protein, and encourages a high-fat content of the diet to supply energy demands. As such, the modified Atkins, as well as the low glycemic index treatment diet, can be considered as a more “natural” approach.


• The ketogenic diet, the modified Atkins diet, and the low glycemic index treatment all require regular medical care, with frequent neurologic and dietary follow-up management.

Historical note and terminology

Many quotations from ancient texts refer to fasting as a cure for seizures. The Hippocratic text Epidemics details a case report in which complete abstinence from food and water resulted in curing the case of epilepsy (Todman 2008). In modern times, as early as 1911, Guelpa and Marie mention the effect of dietary manipulation on epilepsy (Guelpa and Marie 1911). These authors recommended a regimen of fasting, followed by a restrictive and vegetarian diet in the treatment of epilepsy. This history of fasting and the ketogenic diet in the treatment of epilepsy is extensive; it is described elsewhere (Lennox and Lennox 1960; Livingston 1972; Wheless 1995; Freeman et al 1996) and is summarized in Table 1.

Table 1. History of Fasting and Ketogenic Diet in the Treatment of Epilepsy

Circa 30 AD

The Bible states that Jesus Christ recommended fasting associated with prayer for convulsing demon possession (Mark 9:14-29).


“La cure du Dr. Guelpa” was defined as fasting followed by a restrictive and vegetarian diet (Guelpa and Marie 1911).


Geyelin found that fasting suppressed seizures and that his patients remained seizure-free for many months after fasting stopped (Geyelin 1921).


Wilder published his preliminary report on the ketogenic diet in the treatment of seizures (Wilder 1921).


Conklin published the results of the “water diet” (fasting) (Conklin 1922).

1925 and 1927

Peterman and Helmholz published the Mayo clinic experience with the ketogenic diet (Peterman 1925; Helmholz 1927).


Lennox studied the effects of a 2-week fast in the seizure frequency of 5 patients (Lennox 1928; Lennox and Lennox 1960).


Livingston described the methodology and some efficacy data on the ketogenic diet (Livingston 1954; Livingston 1972).


Huttenlocher described the medium-chain triglyceride diet (Huttenlocher et al 1971).

1970s and 1980s

The diet gradually became more unpopular after the introduction of carbamazepine and valproic acid.

There was a decreased need for ketogenic diet due to the perceived advances in the pharmacotherapy of epilepsy.

Medical and neurology residents were taught that valproic acid is a branched-chain fatty acid that can be substituted for the diet with a lesser requirement of family training and teaching (Wheless 1995).


Schwartz and colleagues published the first comparative study of the short-term metabolic effects and clinical efficacy of the “classical” ketogenic diet and the medium-chain triglyceride diets (Schwartz et al 1989b).


Kinsman and colleagues reported the efficacy of the ketogenic diet for intractable seizures in 58 cases (Kinsman et al 1992).

October 1994

Ketogenic diet returned to the media spotlight in an NBC Dateline report (Ketogenic diet 1994) on Charlie Abrahams, a toddler who was successfully treated with the ketogenic diet at Johns Hopkins Hospital by Dr. Freeman and Millicent Kelly, RD. The program increased the awareness about this form of treatment in the medical circles, and it was followed by an increase in research on the effects of the diet. That same year, The Charlie Foundation for Ketogenic Therapies was founded by Jim and Nancy Abrahams (Charlie's parents) to provide information about diet therapies for people with epilepsy.


Wheless described the overwhelming amount of lay press articles and videos for the general public following the NBC documentary (Wheless 1995).


Freeman and colleagues extensively described the classic ketogenic diet method (Freeman et al 1996).

February 1997

Jim Abrahams produced a televised movie called “First Do No Harm”, a televised movie which again turned the public's eye to the diet. The movie was a dramatization of the life of a patient with epilepsy, loosely resembling the case described on the October 1994 “Dateline” program. Today, there are over 200 hospitals worldwide with ketogenic diet centers.

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