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 carbohydrates can stop the ketosis and lead to a breakthrough seizure. Ketogenic diets are usually used as secondary therapy after first-line medications fail if epilepsy surgery is not an option.

The ketogenic diet is the most restrictive. Some clinicians use the Modified Atkins Diet and Low Glycemic Index diets, although they may not be as effective as the ketogenic diet.

A recent meta-analysis showed that seizure frequency reduction was attained in 35-56.1% of the participants in the intervention group, compared with 6-18.2% in the control group. [Sourbron: 2020]

Although GI side effects are the most common complaint, other side effects of the diet include:

• High cholesterol
• Hypoproteinemia
• Growth failure
• Kidney stones
• Osteoporosis
• Impaired immune response
• Disturbances in liver function
• Hemolytic anemia
• Abnormal heart rhythms
• Death

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

Most physicians will recommend the ketogenic diet only after the patient has not achieved seizure control on antiepileptic medication and possibly after surgery has been considered. 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]

Although in the past, most ketogenic diet initiation was done in the hospital, many centers are now using home-based initiation. Intense training regarding the diet is needed for parents. Monitoring of the patient for blood glucose, hydration, and ketosis is started as the diet is initiated. Baseline studies such as EEG, EKG, and metabolic laboratory testing may be performed.

Careful monitoring and education continue until the family is comfortable with the diet. Frequent follow-ups with the pediatric neurologist and dietician are necessary over the first weeks and months after discharge. Families continue to serve the 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 taking these medications and is on the ketogenic diet.

The diet must be carefully calculated each day for the prescribed ratio of fat to protein plus carbohydrates. Adherence and adequacy of the diet are measured with urine dipsticks for ketones.

Unless medical side effects intervene, patients and families should stick to the diet for 2 months before deciding on its efficacy. After a decision 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 limited diet options.