What Is the Ketogenic Diet for Epilepsy?

Medically Reviewed by Carol DerSarkissian, MD on October 14, 2021
Written by WebMD Editorial Contributors
6 min read

Could the solution to your child's epilepsy be a diet loaded with butter, cream, oils, and mayo? It might sound weird -- and maybe not so appetizing -- but the ketogenic diet is real. And in many kids, it works.

But the super high-fat, super low-carb ketogenic diet is not for everyone. It's strict and complicated. And it's not really "healthy" in the normal sense. If you're considering it, you need to think through how it affects your child's life -- and the impact on the whole family.

Some parents of children with epilepsy are skeptical of the ketogenic diet when they first hear about it. A diet that can control epilepsy and stop seizures without any medication? It almost sounds like a scam.

But the ketogenic diet is real and legitimate. The catch is that it's demanding and hard to follow. In fact, it is so difficult to follow that most doctors recommend it only for people who haven't been able to control their seizures with medicine.

The ketogenic diet has been curbing seizures since it was first developed in the 1920s. About half of kids who follow it have a big drop in how many they get. As many as 1 in 7 stop having seizures completely.

The diet helps with many types of epilepsy, but works especially well with Lennox-Gastaut syndrome, myoclonic astatic epilepsy (Doose syndrome), and others. Some pediatric epilepsy syndromes respond very well to the ketogenic diet and most adult epilepsies do not.

Because the ketogenic diet is so demanding, doctors usually only recommend it if a child has already tried two or three medications and they haven't worked.

When the diet works, kids can often lower their medication doses or stop taking them. What's more, most kids who stay on the ketogenic diet for at least 2 years have a good chance of becoming seizure free -- even after they go back to eating normally.

Your child's diet will have a lot of fat. To put it in perspective, in a healthy diet for kids, about 25% to 40% of calories come from fat. In the ketogenic diet, about 80% to 90% of calories come from fat.

So your child's meals are loaded with fats while portions of protein and especially carbs are small. In the typical ketogenic diet, kids get three to four times as much fat at each meal compared to carbs and protein combined.

What does that mean in practice? Most high-carb foods -- like bread, pasta, sweets, and more -- are off the menu. Your doctor will usually start with this first, but there are also modifications. If it works, you can usually step down to more of a modified Atkins and slow introduce carbs. This usually involves carb counting and monitoring ratio of carbs to fats.

Your child may start the diet in the hospital so nurses and doctors can observe the first few days. They will probably need to go without any food for 36 to 48 hours before beginning the diet. After that, food is increased over a few days.

This diet does not provide all the vitamins a body needs, so your child will probably have to take sugar-free vitamin supplements.

Even though it's been around for about a hundred years, we still don't know. Many experts believed it had to do with a process called ketosis. That's where the diet's name comes from. Ketosis happens when your body runs out of carbohydrates to burn for energy and burns fat instead.

This ketosis is the same process that kicks in when someone is fasting -- on purpose or because of starvation. Fasting has been a traditional seizure treatment for centuries.

Researchers at Johns Hopkins University studied 150 children with epilepsy in one important study. After a year on the ketogenic diet, half of children had 50% fewer seizures. One-fourth of the children reduced their seizures by 90%. After a few years on the diet, many of these children no longer needed medications at all.

But many experts aren't sure if ketosis has anything to do with why the diet works. It may be related to some other effect we don't understand.

The ketogenic diet is not something you try out casually. It's a big commitment, and starting it on your own is risky. You and your child need to work closely with a team of experts.

  • Prepare for a few days in the hospital. Doctors often want to keep an eye on kids when they start the diet to make sure they're doing OK.
  • Work closely with a dietitian. The ketogenic diet is tailored to each child. So a dietitian will give you detailed info on exactly what your child can eat and how much. Since the ketogenic diet is low in important nutrients, your child will probably need supplements of calcium, vitamin D, iron, folic acid, and others.
  • Watch out for carbs in everything. Tiny amounts of carbs show up in unexpected places, like toothpaste.
  • See the doctor often. Your child will need regular checkups every 1 to 3 months at first. The doctor will chart their growth and weight, test their blood and urine, keep an eye on cholesterol and decide whether to tweak the diet or medication dose.
  • Stick with the diet for a few months at least. If it works, you should notice fewer seizures by then -- or even sooner. If the diet doesn't help, your child will gradually return to a normal eating plan. If they stop the ketogenic diet suddenly, it could trigger seizures.

Right after your child starts the diet, they may feel tired. Other side effects include:

If your child has side effects, tell their doctor. You may be able to treat them with changes to their diet or medication.

If the side effects are too much for your child, ask the doctor about other epilepsy diets, like the modified Atkins diet and the low glycemic index treatment diet. They can be a little easier to handle.

There can be problems following the ketogenic diet:

  • Weighing food precisely is important.
  • Even little lapses -- like sneaking the crumbs of a cookie or swallowing a nasal decongestant -- can result in a seizure.

As you might imagine, it's a challenge for most parents to keep their children on this diet. Children may accept food from other kids at school or at a friend's house. Older children may have strong opinions about what they want to eat. The ketogenic diet works best in young children who haven't developed strong tastes in food.

Children on the ketogenic diet also often feel very hungry, at least at first. You need to monitor all of the food in the house, including food in the dog's bowl.

You may also be concerned about the effects of eating all that butter and cream. After all, isn't fat supposed to be bad for you? A study confirmed that children on the ketogenic diet do have significantly higher levels of cholesterol than most kids. But damage from a high-fat diet generally comes only after many years. Children usually follow the ketogenic diet for just a few years.

This high-fat/low-carb diet may sound like any number of protein diets you've read about. In fact, some popular protein diets also claim to cause the process of ketosis. But the ketogenic diet is not like a typical protein diet, and you can't do it on your own.

A dietitian can help you adapt the strict rules of the diet to real menus, so you can come up with meals your child may enjoy.

If you're considering the ketogenic diet, don't assume your child will fight the strict rules. Talk it over together and include your neurologist. Your child probably wants the seizures to stop, too, and may cooperate willingly.

You have to decide if your family is ready for the ketogenic diet. You'll need to change the food you have in your home and the meals you eat. That can be tricky if you have other kids in the family.

All caregivers for your child -- from babysitters to teachers -- have to understand the diet and be on board, too. Even a little cheating on the food plan could trigger a seizure.

If you think you're up for it, talk to your child's doctor. Going "keto" is never easy -- but for many kids, it can be a big success.