Patient education: Ketogenic diet (The Basics)

What is a ketogenic diet? — A ketogenic or "keto" diet involves eating foods that are high in fat, moderate in protein, and low in carbohydrates.

Most of the time, the body uses carbohydrates, or "carbs," from the diet as the main source of fuel. With the ketogenic diet, the body breaks down fats into "ketones." It then uses the ketones as fuel for the body.

Is there more than 1 kind of ketogenic diet? — Yes. The "classic" ketogenic diet is a specialized high-fat, moderate-protein, low-carbohydrate diet plan.

Other versions of the ketogenic diet include:

●Medium-chain triglyceride diet

●Modified Atkins diet

●Low-glycemic index diet

●Modified ketogenic diet

Each of these diets is slightly different than the classic ketogenic diet. Some use different amounts of protein or carbohydrates. Others use different kinds of oils (like coconut oil or palm kernel oil) as a source of fat.

Based on your needs, the doctor or dietitian will help you make a diet plan that is right for you.

Why do I need a ketogenic diet? — Doctors recommend this diet as part of a treatment plan for some people with a condition called "epilepsy," which causes people to have repeated seizures. The ketogenic diet can sometimes help control seizures when medicines have not worked. When a doctor recommends a specific diet for medical reasons, a dietitian (nutrition expert) will help plan the diet for the person.

Some people without epilepsy choose to eat a low-carbohydrate or modified ketogenic diet to lose weight or to help with other health problems. Always check with your doctor before you start any diet plan that involves restricting certain types of food.

What do I need to consider before starting a ketogenic diet? — A ketogenic diet can be very restrictive and can affect your lifestyle. Here are some things to think about before you get started:

●Ketogenic diets include very few carbohydrates. You will even need to avoid carbohydrates from otherwise healthy foods like fruits, vegetables, milk, and whole grains.

●You will need to follow the diet very closely for it to have the best chance of working. For example, it's important to finish all of the food with each meal. This is to get the right balance of nutrients for your body.

●Know how to weigh and measure food items. This will help you eat the right amounts of fats, proteins, and carbohydrates.

●Learn about non-food items that can have hidden carbohydrates in them, like medicines or supplements. Even things you don't swallow, like toothpaste, can be absorbed into your body.

●You might need to take more time to plan meals. Meals might also cost more on this type of diet.

●You will need to take additional vitamin supplements to maintain your health.

●Many people will still need to take medicines to treat their seizures.

●Talk to your doctor about how long you will need to be on this diet.

●You will want to work closely with a dietitian to plan menus to make sure you will have the right balance of fats, proteins, and carbohydrates in your diet.

●Keep tempting foods that are not suggested on this diet out of reach.

Are there any side effects of a ketogenic diet? — Some side effects are common and usually easy to manage while on a ketogenic diet. Examples include:

●Diarrhea

●Constipation

●Nausea and vomiting

●Heartburn

●Low blood sugar

●Kidney stones

Other common side effects include:

●High blood cholesterol levels

●Weakened bones

●Kidney stones

●Slower growth in children

Less common but serious side effects might include:

●Changes in heart rhythm

●Pancreatitis (inflammation of the pancreas)

What follow-up care do I need? — The doctor will want to see you again after you start this diet to check on your progress. Be sure to go to these appointments. The doctor might want to change your medicines. You might also need to have tests to check how the diet is working.

What else do I need to know? — The doctor might want you to stay in the hospital for the first few days when you start this diet. The doctors and nurses will be able to watch you closely and help you learn more about what you can eat and what foods you should avoid. Sometimes, the doctor will want you to fast (not eat anything) for 24 hours before beginning the diet.

You will know if the diet is working within a few months. If the diet is working, you can stay on it for a long time. Sometimes, after a couple of years on the diet, the doctor might have you try to "wean" off the diet and see if the seizures return. This means gradually returning to a normal diet. This weaning process takes a few months.

More on this topic

Patient education: Seizures (The Basics)
Patient education: Epilepsy in adults (The Basics)
Patient education: Epilepsy in children (The Basics)
Patient education: Epilepsy and pregnancy (The Basics)
Patient education: Ketogenic diet and your child (The Basics)

Patient education: Seizures in adults (Beyond the Basics)
Patient education: Seizures in children (Beyond the Basics)
Patient education: Treatment of seizures in children (Beyond the Basics)