What is a Ketogenic Dietary Therapy?

A Ketogenic diet is more than its title suggests – it is NOT some fad diet that is currently ‘fashionable’. It is a proven medical therapy for epilepsy based on a diet that is high in fat, adequate in protein and low in carbohydrate. It MUST be managed by a qualified ketogenic dietitian in partnership with neurologists /doctors. It is clinically proven to be highly effective in managing difficult to control epilepsies, as well as metabolic disorders such as GLUT1 deficiency, with research currently being conducted looking at the diet as a therapy for a range of long-term neurological diseases and cancer.

The diet was first developed in the USA in the 1920’s and was used for children and adults. With the advent of newer anti-seizure medication in the 1930’s-1970’s interest in the diet waned. The 1990’s, however, saw a resurgence of interest in the diet for children. In the 1970’s the MCT (medium chain triglyceride oil) version of the diet was also introduced.

Types of Ketogenic Therapy

All types of the diet are based on regular fresh food; meats, fish, eggs, nuts, seeds, cheese, vegetable oils, butter, cream, vegetables and fruits.

  • Classical ketogenic diet – where carbohydrate, fat and protein amounts are all measured and carefully distributed to maintain a similar balance (ketogenic ratio) at meals and snacks.

  • MCT ketogenic diet – where carbohydrate, fat and protein amounts are all measured and medium chain triglyceride oil which is a refined coconut oil, is included with each meal/ snack. This enhances ketosis and allows more carbohydrates in meals and snacks.

  • Modified ketogenic diet and Modified Atkins diet – not so restrictive on protein foods but requires measurement of carbohydrate foods and adequate portions of fats at meals.

  • Low Glycaemic Index Treatment – very similar to the Modified ketogenic diet approach in terms of measuring carbohydrate and encouraging fats but restricts the carbohydrate sources to those with a glycaemic index of 50 or below.

Ketogenic dietary therapies can be administered as a normal oral diet, via a bottle feed, or tube feed and specific formulas are available.

These diets can be tailored to patients’ specific requirements which could mean incorporating elements of all the above diets as we seek to optimise the effects.

Ketogenic Therapy for Epilepsy – How the Diet works

There is much research in this area. The diet appears to “mimic starvation” by using fat as an alternative fuel source for the body, producing ketones. These ketones and the associated biochemical changes in the brain, can have an anti-seizure effect.

The “Holy Grail” of the ketogenic diet is for a patient to be initiated on the diet, become seizure free, reduce/remove the amount of anti-seizure medication taken, wean the diet off after a period of 2 years and STAY seizure free. This DOES happen for some, but there are also other degrees of success on the diet:

  • Reduction in number of and intensity of seizures

  • Reduction in drugs and their subsequent side effects

  • Increased alertness

  • Improvement in behavioural problems

  • Improvement in learning ability

  • QUALITY OF LIFE!

Who is ketogenic therapy suitable for?

Ketogenic therapy should be considered as a treatment for epilepsy after two appropriate anti-seizure medications have failed to be effective or produced unacceptable side effects. This treatment has been shown to be successful in treating a wide range of seizure types and syndromes although may be particularly beneficial in myoclonic epilepsies, infantile spasms and tuberous sclerosis complex. Guidelines from the UK National Institute for Health and Care Excellence (NICE), updated in April 2022, recommend the following:

Consider a ketogenic diet under the guidance of a tertiary epilepsy specialist, in people with:

  • glucose transporter type 1 deficiency syndrome (GLUT1 deficiency syndrome)

  • epilepsy associated with pyruvate dehydrogenase deficiency

  • infantile spasms syndrome

  • epilepsy with myoclonic-atonic seizures (Doose syndrome)

  • Dravet syndrome

  • Lennox–Gastaut syndrome

  • Drug resistant Epilepsy – if other treatment options have been unsuccessful or are not appropriate.

https://www.nice.org.uk/guidance/ng217/chapter/8-Non-pharmacological-treatments#ketogenic-diet

Contraindications

Ketogenic therapies are not suitable for those individuals who have the following conditions:

  • fatty acid oxidation defects

  • pyruvate carboxylase deficiency

  • primary carnitine deficiencies,

  • organic acidurias,

  • defects in ketone metabolism,

  • disorders that require high dietary carbohydrates as part of their treatment

  • severe liver disease

  • hypoglycaemia under investigation.

They should be used with caution in those with a history of:

  • renal stones

  • hyperlipidemia

  • severe gastro-oesophageal reflux

  • diabetes mellitus

Certain family circumstances may also hinder the management of the diet and also some treatments such as steroid use may also interfere with this therapy.

Although possible, ketogenic therapy will be more difficult to implement if there are pre-existing dietary restrictions and food allergies, especially if associated with behavioural feeding issues. A ketogenic diet can be administered to enterally-fed individuals via naso-gastric tube or gastrostomy.

All types of diet have been shown to be successful in the treatment of epilepsy. Choice will depend on the individual’s age, dietary preference and lifestyle, taking into account palatability and ease of use for both the child/adult and the family.

Useful External Links

For general information, recipes, resources and more from the Ketogenic Dietary Therapies charity

For video recipe demonstrations & cooking tips

Visit the Ketogenic Dietitians Research Network website here

A visual resource for families to help ‘Build a Keto Meal’

The International Neurological Ketogenic Society website for health professionals & links to the series of Global Symposium meetings held biannually