Ketogenic diet for epilepsy (children)

This is currently a pilot service at Chelsea and Westminster Hospital funded by the charity Matthews Friends.

What we do

We are committed to advancing care for children with epilepsy. We are proud to introduce our new pilot service for ketogenic diets, offering families another option when medications have not been successful. Guided by our expert team of a neurologist, dietitian and nurse, we tailor the ketogenic diet to each child to ensure safety, nutritional adequacy, ongoing support and the best possible outcomes.

What it is and how it works

The ketogenic diet is a special high-fat, low-carbohydrate diet that has been shown to help reduce seizures in children with drug-resistant epilepsy. It works by changing the way the brain uses energy. Instead of glucose (from carbohydrates), the brain uses ketones (produced from fat). We carefully calculate the diet to suit each child depending on their age, growth and activity level.

It is a medical diet that requires monitoring of seizures, side effects and blood ketones and glucose using finger-prick tests.

We do not know exactly why the diet has an anti-epileptic effect. However, research suggests there could be several reasons, including changes to the gut microbiome affecting the gut–brain axis, and biochemical changes in the brain that reduce seizure activity.

Benefits

The ketogenic diet has been shown to significantly reduce seizures in about half of the children who start it. A small number of children may even become seizure-free.

For some children, anti-epileptic medications can be reduced, which may lessen side effects. Families also often report improvements in quality of life, behaviour, learning, development and awareness.

Types of ketogenic diet

We offer the most widely used ketogenic diets in the UK, including the Classical, Modified and Medium Chain Triglyceride (MCT) ketogenic diets. They all serve the same purpose but are chosen according to individual needs.

  • Classical Ketogenic Diet: Carbohydrate, fat and protein are all measured and carefully distributed to maintain a set balance (ketogenic ratio) across meals and snacks.
  • Modified Ketogenic Diet: Allows moderate protein intake and requires measurement of carbohydrate foods and fats.
  • MCT (Medium Chain Triglyceride) Ketogenic Diet: Carbohydrate, fat and protein are all measured, and MCT oil or emulsion is included with each meal or snack. This enhances ketosis and allows a slightly higher carbohydrate allowance.

Foods excluded (high carbohydrate)

  • Foods high in sugar, including sweets, some fizzy drinks, puddings, chocolate and cake
  • Bread
  • Rice
  • Pasta
  • Cereals and grains

Allowed in small amounts

  • Dairy products (which contain a natural sugar called lactose)
  • Fruit
  • Vegetables, particularly starchy vegetables such as potatoes, butternut squash, cassava, pumpkin, yam and parsnips
  • Pulses such as peas, beans and lentils

Before starting the ketogenic diet

It is important to make sure the ketogenic diet is safe and suitable for your child. Before starting, we carry out a series of checks, including:

  • Blood and urine tests
  • Weight and height measurements
  • A medication review
  • A review of your child’s seizure types and frequency
  • A review of your child’s current diet

When your child has started the ketogenic diet

Once your child begins the ketogenic diet, our team will support you throughout. Our dietitian will be in regular contact to review progress, monitor ketone levels and check your child’s growth. The diet may be adjusted during the early stages.

We ask parents to commit to at least three months to assess whether the diet is having a beneficial effect. If it is effective, the diet is usually continued for around two years before we discuss whether to gradually wean off or continue.

Our team

We are based at Chelsea and Westminster Hospital. Our team includes a consultant paediatric neurologist, a specialist dietitian and the paediatric epilepsy nursing team.

Further information

Supported by Matthew’s Friends Charity.

FAQs

What types of food will my child be able to eat?

Your child will still be able to enjoy a wide variety of foods on the ketogenic diet. This list is a good starting point and will expand as you become more confident with recipes:

  • Fat – double cream, mayonnaise, oil, butter
  • Protein – chicken, bacon, ham, mince, salmon, tuna, eggs, cheese
  • Carbohydrate – fresh or frozen vegetables such as broccoli, swede, cauliflower, mushrooms, peppers, spinach, spring onion, lettuce; low-carb fruit such as melon, strawberries, blackberries, kiwis, raspberries, blueberries

Will meals look similar to what my child eats now?

Yes. Your dietitian will calculate ketogenic recipes for many familiar foods and snacks. Examples include scrambled eggs and bacon, omelettes, Bolognese, pizza, roasts, quiche, salads, tuna mayo, chicken nuggets, bread, muffins, pancakes, waffles, cookies, puddings, yoghurt, fruit shakes, ice cream and ice lollies.

Will my child feel hungry?

Although portion sizes are smaller than on a typical diet, meals provide the right number of calories, calculated by your dietitian. They also contain more fat, which keeps your child feeling full for longer, so hunger should not be a problem.

What happens if my child attends nursery, school or respite care?

Parents or carers are expected to provide food for their child, or agree suitable options with staff in advance. It is important that intake is monitored and reported back to parents, especially if food is not eaten or if the child eats something outside their plan.

Can we still eat out and go on holiday?

Yes. Most restaurants and cafés are happy to accommodate special diets, though it is best to contact them beforehand to check suitable options. The ketogenic diet also travels well, and with a little planning many families enjoy holidays both in the UK and abroad.

How long does it take for the diet to work?

Some children improve within a week, while others may take up to three months or longer to show a response.

Is the ketogenic diet bad for the heart?

Although the diet is high in fat, the fat is converted into ketones, which are used by the brain for energy. Current evidence suggests this does not increase the risk of heart disease. Cholesterol levels will be monitored while your child is on the diet.

What happens if my child eats foods not allowed on the diet?

Ketogenic therapy should be treated like medication. If your child eats or drinks foods high in carbohydrates, such as sweets or juice, it can trigger seizures. The effect is similar to missing a dose of their antiseizure medicine.

For clinicians

This is currently a pilot service at Chelsea and Westminster Hospital.

The ketogenic diet is a high-fat, moderate-protein and very low-carbohydrate diet designed to induce ketosis. Current evidence suggests that around 50% of children on the diet achieve at least a 50% improvement in seizure control.

The ketogenic diet is usually reserved for children who have not responded to anti-epileptic medications. Our team provides an outpatient service for children over the age of 2 years—we do not initiate the diet in an inpatient setting. Due to its restrictive nature, the diet requires significant commitment from parents or caregivers to learn and manage at home. Prescriptions are calculated individually by the ketogenic dietitian, and each family receives ongoing support from the ketogenic team.

Risks

The ketogenic diet may cause short- and long-term side effects. At the start, children may experience nausea, abdominal discomfort, constipation, diarrhoea or increased tiredness. These symptoms can usually be managed medically, with dietary adjustments, or may resolve over time. Many patients are generally more alert in the longer term. Possible long-term risks include kidney stones, slowed growth, high cholesterol and osteopenia with increased risk of fractures. Rare side effects include pancreatitis, rash and easy bruising.

Medications

Any medications, supplements or vitamins taken while on the ketogenic diet must be as low in carbohydrate as possible. Tablets and capsules that can be swallowed or crushed are preferable. Syrups, elixirs and chewable tablets should be avoided where possible. There are no contraindications to injections, such as vaccinations or antibiotics, in relation to the diet.

Monitoring

The ketogenic diet requires regular monitoring of nutritional, neurological and biochemical markers. These are reviewed in clinic alongside regular contact between appointments. The diet may be discontinued if a 50% improvement in seizures is not achieved after at least 3 months. If benefits are seen, it is usually continued for 2 years.

Managing illness and hospital admissions

Families will receive guidance on managing illness at home and what to consider if their child is admitted to hospital. Clinical guidelines are available to clinicians on the intranet and directly from our team.

Next steps

After two years, and once your child has successfully weaned off the diet, care will be transferred back to the referring paediatrician or neurologist for continued monitoring.

Referrals

We accept referrals from secondary and tertiary care only. We do not accept referrals from GPs. Referrals can be made externally or internally via email using our referral form.

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