The ketogenic and related diets

This information describes what the ketogenic diet is, why medical supervision is needed for it, who it’s for and how to access the service.

The ketogenic diet

The ketogenic diet (also called ketogenic therapy) is a specialist medical diet. It’s a treatment option for people with epilepsy whose seizures can’t be reduced or stopped with epilepsy medicine. It’s recommended in the National Institute for Health and Care Excellence (NICE) guideline for the management of epilepsy which is difficult to control.

The ketogenic diet is much higher in fats and lower in carbohydrates than a typical diet.

If you think your child might benefit from the ketogenic diet, you will need to discuss this with an epilepsy specialist. The ketogenic diet is gradually becoming a treatment option for adults too. But using it for adults is not yet part of the NICE guidance. This can make transition to adult services difficult for teenagers on the ketogenic diet. 

How does the ketogenic diet work?

We don’t completely understand how the ketogenic diet works but there is some evidence that the brain needs energy from glucose (a sugar) to create a seizure.  The ketogenic diet makes the body think that it’s in a state of starvation or fast. In this situation, our bodies use fat instead of carbohydrates (complex sugars or starches) as the main energy source. So the ketogenic diet gives a much higher amount of fat than is found in a normal diet, enough protein for growth and a very small amount of carbohydrate. This makes the body’s ketones. The brain uses these for energy instead of glucose. It also reduces the amount of glucose available for the brain.

Why do you need medical supervision to go on this diet?

The ketogenic diet is not a ‘natural’ treatment for epilepsy as it’s not a natural diet. It should only be managed by a team of a paediatrician and a paediatric dietitian who are experts in the diet. This is because the balance of the diet needs to be carefully worked out for each child and because vitamins and other special supplements are needed. It is not advisable as a treatment option for some children with some metabolic disorders or other neurological disorders.

Children can have a very individual response to the ketogenic diet. Some will have unwanted effects including weight loss, constipation or diarrhoea and high cholesterol. The doctor should be able to manage most of these. But some children may not tolerate the side- effects. Some children have other medical conditions that mean the diet is not suitable for them at all . Some will have difficulty taking all of the fat that is needed to produce ketones and occasionally a feeding gastrostomy tube may be inserted to help in these children. 

Does the diet work?

Studies have shown that about half of children will have a good response to the ketogenic diet and some will become seizure free. You may notice that your child appears more alert as well. However, the ketogenic diet does not work for every child, and it is not possible to predict who it will help.

The modified ketogenic diet

There are 2 modified ketogenic diets. These are the modified Atkins diet (MAD) and the low glycaemic index treatment (LGIT) diet. The MAD is low in carbohydrates but high in fat. Protein is not restricted. On the LGIT diet carbohydrates and protein are both restricted and fat is positively encouraged.  These 2 modified diets are less strict than the ketogenic diet and weighing of food is not needed. The MAD is increasingly being chosen for children. 

Can adults use these diets?

There is limited evidence for how effective or tolerable the ketogenic diet is for adults. But because, as an adult, you can choose what you eat, you may well find the modified ketogenic diets are easier to tolerate.

It is still important to have some medical guidance for these diets, especially if you have any other health conditions or take other medicines.

There are some adults clinics available through the NHS. There are also a few private clinics around the country for adults wanting to try the ketogenic diet. The ketogenic diet was initially introduced for children. There is not yet enough evidence to convince the NHS to provide adult clinics more widely.

How can I get a referral for my child?

If you would like your child to try the ketogenic diet you should ask your paediatrician to make a referral to your local ketogenic diet clinic. Most teaching hospitals in cities in the UK have a service for children.

How can I get a referral as an adult?

If you are an adult you should ask your GP to refer you to an adult epilepsy specialist to discuss this as an option. If there is no local NHS service, they may refer you to the clinic offered by the charity Matthew's Friends.  

What does Matthew’s Friends offer?

The Matthew’s Friends charity provides a huge amount of information, training, research and support for medical ketogenic dietary therapies. This is for medical professionals, families and patients. It includes their website, YouTube tutorial and cooking channels and social media.  They have online ketogenic support forums for families on Facebook and a professional forum on their website. They also provide online training tutorials.  For detailed information on the various ketogenic dietary therapies for children and adults go to their main website.

Website: Matthews Friends

Matthew’s Friends clinical service
Matthew’s Friends also have a clinic in Surrey based with the epilepsy organisation Young Epilepsy. This offers support on medically supervised diets for children and adults, where there is no local service available. To support local services, they help fund dietitians in the NHS around the country. You can only be referred to the Matthew’s Friends clinic by a doctor.  Matthew's Friends also take private patients and referrals from overseas. You would need to make a funding application - talk to your family doctor about how to make an application.
Website: Matthews Friends clinics

What does Daisy Garland offer?

Daisy Garland offers information about childhood epilepsy, the ketogenic diet and the Modified Atkins diet. To support local services, they also help fund dietitians in the NHS around the country.

Useful organisations

Matthew's friendsMatthew’s Friends

Daisy Garland

If you would like to see this information with references, visit the Advice and Information references section of our website. If you are unable to access the internet, please contact our Epilepsy Action Helpline freephone on 0808 800 5050.


This information has been produced under the terms of Epilepsy Action's information quality standards.

  • Updated November 2019
    To be reviewed November 2022

Comments: read the 2 comments or add yours


My son of 17 has recently been diagnosed and reading about high fat ketonic diet makes me wonder whether a high carbohydrate diet might be detrimental for someone with epilepsy?

Submitted by Michael Shaw

Hi Michael

Thank you for your message.

It’s not yet completely understood how the ketogenic diet works. And we don’t know if there is any evidence that a diet high in carbohydrates could have a detrimental effect on someone’s epilepsy.

If you have any specific concerns about your son’s diet and his epilepsy, or want to know more about the ketogenic diet, it may be a good idea to talk to his epilepsy specialist, epilepsy nurse or family doctor.

There are also 2 modified ketogenic diets. These are the Modified Atkins diet (MAD) and the low glycemic index treatment (LGIT) diet. They also involve restricting carbohydrates and encouraging fats but are less strict than the ketogenic diet and weighing of food is not needed. It is still important to have some medical guidance for these diets, especially if you have any other health conditions or take other medicines. But they work well for some people with epilepsy and can be easier to tolerate than the ketogenic diet.



Epilepsy Action Helpline Team

Submitted by Jess - Epilepsy...

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