KETOGENIC DIET EPILEPSY

What is the ketogenic diet? 

The ketogenic diet is a high fat, low carbohydrate, and adequate protein diet that has been utilized for decades in the treatment of drug-resistant epilepsy in children. This diet mimics the metabolic state of fasting, which can be particularly beneficial for managing seizures. 

When is the ketogenic diet indicated in children with epilepsy? 

Approximately 30% of children with epilepsy develop drug-resistant epilepsy, characterized by persistent seizures despite adequate trials of two anti-seizure medications. The ketogenic diet in children has shown notable clinical success, with 48% of individuals achieving more than a 50% reduction in seizure frequency or even seizure freedom. 

How does the ketogenic diet work? 

Typically, the brain uses glucose for energy. However, during fasting, fatty acids provide energy for muscles and other tissues, while ketones are generated from these fatty acids. Young children are able to extract and utilize ketones in the brain three to four times more effectively than older individuals. The degradation of fats produces ketones, which serve as an alternative fuel for body tissues and exert an anti-seizure effect in the brain. 

What tests are needed before starting the ketogenic diet? 

If a child has any conditions that prevent them from utilizing fats in the body, this represents a contraindication to the ketogenic diet. Therefore, a comprehensive set of blood tests is performed, including nutritional assessments and tests to rule out any metabolic disorders that would be contraindicated for the ketogenic diet. 

What are the different kinds of ketogenic diets? 

1. Classic Ketogenic Diet: A 3:1 or 4:1 ratio of fats to carbohydrates, with 90% of calories coming from fat, 5% from protein, and 5% from carbohydrates.  

2. MCT Oil Diet: 30-60% of calories from MCT oil/fats, 10-15% from protein, and 10-15% from carbohydrates.  

3. Modified Atkins Diet: Unlimited protein with carbohydrates limited to 10-20 grams per day.  

4. Low Glycemic Index Diet: Carbohydrates are limited to 40-60 grams per day, focusing only on those with a glycemic index of less than 50.  

Your doctor will select the most suitable diet for your child, and a specialist in pediatric neurology and ketogenic diet will guide you through the process. 

What can I expect from a consultation with a ketogenic dietician? 

During the consultation, the dietician will assess the child's weight, height, and BMI, along with a three-day food diary to evaluate current eating patterns. They will match calorie intake and recommend recipes tailored to the selected ketogenic diet for your child. 

Is it possible to do the ketogenic diet as a vegetarian? 

Yes, it is definitely possible to follow a vegetarian ketogenic diet. Your doctor and dietician will provide guidance on how to achieve this. 

What monitoring is needed during the ketogenic diet? 

Generally, monitoring devices for blood sugar and blood ketones, as well as urine ketones via dipsticks, will be used throughout the diet. 

What are the side effects? 

Short-term side effects may include nausea, vomiting, low blood sugar, sleepiness, and food refusal. Long-term issues may encompass renal stones, constipation, growth problems, bone demineralization, and fractures. Therefore, regular consultations with your pediatric neurologist and ketogenic dietician will be essential, alongside routine blood tests and potential medications to manage side effects. Most side effects can be effectively managed by your healthcare provider. 

How do I know that the ketogenic diet is working? 

We recommend keeping a seizure diary before starting the ketogenic diet and for three months after initiating it. If the diet proves effective, it is usually continued for two years. In some cases, it may be extended beyond this period. A significant percentage of children—almost 80%—who are seizure-free on the ketogenic diet will remain so after discontinuation of the diet. 

Important message for parents: 

Never start the ketogenic diet on your own; always adhere to the advice of your doctor and dietician. 

The ketogenic diet serves as a form of medicine through food. When it is effective, it can significantly improve your child's and family's quality of life.

References :

1. 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; Charlie Foundation; Matthew's Friends; Practice Committee of the Child Neurology Society. Optimal clinical management of children receiving dietary therapies for epilepsy: Updated recommendations of the International Ketogenic Diet Study Group. Epilepsia Open. 2018 May 21;3(2):175-192. doi: 10.1002/epi4.12225. PMID: 29881797; PMCID: PMC5983110.

2. Figueroa AG, Joshi CN, Patel MN. From clinical practice to mechanistic insights in ketogenic diets for epilepsy. Lancet Neurol. 2026 Mar 11:S1474-4422(26)00008-6. doi: 10.1016/S1474-4422(26)00008-6. Epub ahead of print. PMID: 41831475.

Dr Rashmi Adiga, 

MBBS, DCH, MRCPCH(U.K), CCT(U.K), FRCPCH.

Consultant Paediatric Neurologist