Ketogenic diet and how it can form part of the treatment of childhood epilepsy

When a child has epilepsy, the first approach usually relies on medication aimed at preventing or reducing seizures, but these do not always produce the expected results. When two appropriately selected and properly used drugs fail to achieve sustained control, this is known as drug-resistant epilepsy. From that point, different options can be considered, and one of them may come as a surprise to many families: making very precise changes to what the child eats.

Among these strategies is ketogenic therapy, based on a diet that is high in fat and significantly restricts carbohydrates. Its purpose is not weight loss or to replicate the popular “keto diet”, but to trigger metabolic changes that may influence brain activity. It is a clinical strategy that can help reduce seizure frequency in certain types of childhood epilepsy. The International League Against Epilepsy (ILAE) recognizes it as an established non-pharmacological approach, while NICE guidelines recommend considering it in specific situations under specialist supervision.

Changing the fuel the brain uses

Under normal conditions, glucose derived mainly from carbohydrates is one of the body’s primary sources of energy. A ketogenic approach significantly reduces these nutrients, increases the proportion of fat and maintains the protein needed to support growth. In response to this change, the liver produces ketone bodies, which can be used as an alternative source of fuel, including by the brain.

However, the explanation for its antiseizure effect goes beyond simply “producing ketones”. Research points to changes in neurotransmitter activity, mitochondrial function, neuronal excitability and certain processes related to neuroinflammation and oxidative stress. In recent years, the possible role of the gut microbiota has also attracted increasing interest, suggesting that there is no single mechanism involved, but rather several metabolic changes capable of influencing brain activity.

This way of approaching the condition is not new. It began to be used more than a century ago, although it lost prominence with the arrival of new antiseizure medications and regained attention decades later, particularly for patients who did not respond sufficiently to them.

There is no single ketogenic approach

The classic version is the most restrictive: it establishes a specific ratio between fats and the combined amount of protein and carbohydrates, and food quantities are calculated very precisely. Today, however, other options are also available, including the modified Atkins diet, medium-chain triglyceride therapy and low glycaemic index treatment.

This range of approaches makes it possible to adapt the strategy according to age, diagnosis, energy requirements, eating patterns and each family’s circumstances. Not every patient requires the same level of restriction to benefit, and this flexibility becomes particularly important when these approaches need to be maintained over long periods.

A randomized trial published in 2025 compared the modified Atkins diet with low glycaemic index treatment in 91 children with drug-resistant epilepsy. After 24 weeks, both groups had experienced substantial reductions in seizure frequency, with no statistically significant difference between them. The study reflects the ongoing interest in finding alternatives that may preserve clinical effectiveness without always requiring the most restrictive regimen.

When can it be considered?

It is not prescribed for every diagnosis. NICE recommends considering it in certain syndromes and in drug-resistant cases when other options have been insufficient or are not appropriate.

These include Dravet syndrome, Lennox-Gastaut syndrome, infantile spasms and epilepsy with myoclonic-atonic seizures. It also plays a particularly important role in two metabolic disorders: glucose transporter type 1 deficiency, known as GLUT1 deficiency, and pyruvate dehydrogenase deficiency.

In these two conditions, where there is a problem affecting how the brain receives or uses glucose, ketone bodies can provide an alternative energy source and partially bypass the underlying metabolic defect. In fact, international consensus considers ketogenic therapies a first-line option for both disorders.

For this reason, simply referring to a “diet for epilepsy” would be inaccurate. Whether it is indicated depends on the cause, the type of condition, the approaches previously used and the individual characteristics of each patient.

What results can be expected?

Response varies between patients, and the goal is not always to achieve the complete disappearance of epileptic episodes. The ILAE states that around half of children who begin ketogenic therapy achieve at least a 50% reduction in the number of seizures, while a smaller proportion become seizure-free.

The studies available so far support its usefulness particularly in drug-resistant epilepsy, although results vary depending on the type of approach used, the diagnosis and the length of follow-up.

A meaningful reduction can have an important impact on safety and quality of life even when seizures are not eliminated completely. For this reason, progress is not assessed solely by counting episodes. Their severity, the need for other medications, alertness, development and the patient’s overall condition may also be taken into account.

Therapy accompanied by follow-up

Making such a significant change to the usual distribution of nutrients can also cause side effects. A study published in 2025 on the classic approach identified both short- and long-term complications, including gastrointestinal problems and metabolic alterations. Vitamin and mineral deficiencies, changes in lipid levels and kidney stones may also occur.

To reduce these risks, a medical and nutritional assessment is carried out before starting to confirm that this option is appropriate and to rule out certain metabolic disorders in which it could be dangerous. Growth, blood test results, tolerance and neurological progress are then monitored. Supplements may also be required to ensure an adequate intake of micronutrients.

This is why it cannot be safely replicated by following meal plans found online. Even some syrups, medicines or supplements may contain carbohydrates and need to be reviewed to prevent them from interfering with an approach designed around very specific quantities.

The challenge of maintaining it

Once established, much of the effort moves into everyday life. Families may need to weigh food, check labels, prepare specific recipes and coordinate meals around school, travel, birthdays or celebrations. For a child, eating also has a social dimension, and maintaining significant restrictions over a long period can be difficult.

For this reason, the choice does not depend solely on which option is the most restrictive. Effectiveness, safety, nutritional development and the real possibility of integrating it into daily life all need to be balanced. A strategy that works on paper loses much of its usefulness if it is impossible to maintain correctly over time.

The relationship between nutrition and childhood epilepsy shows just how far the management of a neurological condition can extend beyond medication. In some patients, changing the way the body obtains energy can influence brain activity. And it is precisely at that point that what reaches the plate stops being a secondary matter and, when carefully calculated, becomes part of the treatment.