What is ketogenic diet therapy?
Ketogenic diet therapy is used as a treatment for epilepsy in children. It is usually tried in children for whom surgery is not an option, if two or more anti-epileptic medications have failed to control seizures or if the medications cause very severe side effects.
All ketogenic diet therapies provide at least 70% of the child’s calories from fat, . The ketogenic diets are adjusted over time for seizure control and with these changes, most children will eat at least 85% of their calories as fat. This means children eat mostly fatty foods such as oils and butter. Most ketogenic diet therapies do not allow any starchy foods such as breads, pastas or cereals.
These ketogenic diets are prescribed as a medical treatment for children with medically intractable epilepsy (epilepsy that cannot be controlled by medication). As they are a medical treatment, they are much more restrictive than the mainstream ketogenic diets that have become popular in recent years. With this level of dietary restriction, there is the potential for significant side effects; careful monitoring by your child’s health-care team and strict adherence to the diet by the child and family are necessary.
What are the benefits of traditional/classic ketogenic diet therapy?
Although it does not work for every child, ketogenic diet therapy has been shown to reduce seizures, even in children whose seizures have failed to be controlled with medication. In some children, it may eliminate seizures altogether. The diet may start to work to control your child’s seizures as soon as one week after starting, but it usually takes several months to judge whether it will be effective. If it successfully controls seizures, it may be continued under the guidance and monitoring of your child's doctor. There is no maximum amount of time that a child may be treated with a ketogenic diet therapy.
Ketogenic diet therapy may also have some other positive side effects, including improvements in mood, behaviour, attention and social functioning.
Ketogenic diet therapy is primarily used to treat epilepsy. However, there are some metabolic disorders in which the body is unable to efficiently use carbohydrates as a fuel, including glucose transporter protein deficiency and pyruvate dehydrogenase deficiency. The ketogenic diet is a preferred treatment for these conditions as well.
Limitations and side effects of traditional/classic ketogenic diet therapy
Ketogenic diet therapy may cause mild side effects in some children, including dehydration, constipation, vomiting, high cholesterol and kidney stones (due to uric acid build-up in the blood). Some families notice mood changes such as hyperactivity or irritability.
More severe side effects include loss of bone density, changes in the blood electrolytes (e.g., low sodium), changes in heart rhythm and poor growth. Neutrophils (white blood cells that help fight off infections) could be low, possibly increasing the risk of infections.
Your child will need to take many vitamin and mineral supplements. Your child's ketogenic diet therapy team can advise you on these.
Some side effects, such as poor growth, are reversed once the child goes back to their normal diet. Other side effects, such as constipation, can be treated based on recommendations from your child's ketogenic diet therapy team. Other effects need to be closely monitored by your child's ketogenic diet therapy team. Ask your child's ketogenic diet therapy team to explain all possible side effects, what you should watch for and what action you should take for each one.
Points to consider before trying traditional/classic ketogenic diet therapy
- The ketogenic diet is very restrictive. It controls the type of food and the quantity of food your child eats. Some children may feel isolated at school because they cannot eat "normal" food.
- The ketogenic diet may have additional financial costs (i.e. cost of buying additional or different food, formulas that are not covered under financial assistance programs, supplements, and equipment) that are a barrier for some families.
- The ketogenic diet will not work unless it is followed carefully, and some children are unable or unwilling to follow it.
- Meals and snacks can be time-consuming and tedious to prepare. This usually gets easier as families adapt to the new routine.
- It is not a balanced healthy eating regimen for the long term.
- It might not work for some children, no matter how closely they follow the diet.
- It is not safe for children with certain metabolic disorders, such as fatty acid oxidation defects.
- The diet has some potentially serious medical side effects. Children must be followed closely by a doctor as they follow the ketogenic diet.
Starting traditional/classic ketogenic diet therapy
Before starting one of the ketogenic diet therapies, your child will need to be seen in a ketogenic diet clinic for a full evaluation by the ketogenic diet therapy team members. Your child will need a physical examination, with measurement of their height and weight and several different blood and urine tests.
The team will also ask for a history for your child’s diet, including:
- What they eat at home
- What they do and do not like to eat
- How much they eat
- Whether you see any problems feeding them the diet
- Whether your family has any cultural or religious food restrictions
The ketogenic diet is usually started in the hospital. Your child will be admitted to hospital for up to 4 days.
As your child begins the diet, ketones will appear in the blood and urine. These will be measured at regular intervals. Your child's blood glucose (sugar) levels will also be measured.
The diet is gradually introduced over 1 to 2 days so the body can get used to the change in food. Supplements of vitamins and minerals are also given to maintain a balance. Water and fluids may be restricted or encouraged, depending on the individual child.
While in the hospital, your child will be closely monitored with urine and blood tests, and they will be watched for any side effects such as low blood sugar, vomiting, constipation, dehydration or lethargy (little to no energy). Your child may feel a bit tired during this initial period as their body is getting used to the diet.
Some diet therapies are started without a hospital admission. However, thorough training of caregivers is still required.
Learning to use traditional/classic ketogenic diet therapy
The ketogenic diet team will teach you how to provide the diet. A dietitian will explain how to plan menus, what food to use, how to read nutrition labels, how to prepare the food, quantities, feeding times and side effects to watch for. They will give you vitamin and mineral supplements that your child will need and explain where to buy more.
They will also help you with strategies for dealing with problems you may encounter while your child is on the diet, including illness, hunger, refusing food, dehydration, constipation, low blood sugar and high or low ketones.
A nurse will teach you how to measure your child's blood sugar and urinary ketones and how to keep track of their body weight, fluid intake and seizure activity.
The ketogenic diet team will monitor your child’s overall wellbeing as well as teach you how to monitor and manage the potential side-effects of the ketogenic diet.
Once the diet is established, there are no complications and you have been taught how to continue with the diet at home, your child will be discharged from the hospital. The ketogenic diet team will explain what to do if you have any questions once you have left the hospital.
Using traditional/classic ketogenic diet therapy at home
Following the diet closely is very important to ensure your child has given it the best chance to work and to see if it can control your child's seizures. It will take several months of diet therapy to see if it reduces your child's seizures. However, straying from the diet, for example eating a couple of cookies, can have an almost immediate negative effect. If you find the diet too restrictive, speak to your ketogenic diet therapy team to discuss ways to alter it to make it easier to use. Changes to the diet could mean changes to food content, quantity or scheduling.
Follow up appointments for traditional/classic ketogenic diet therapy
Children on ketogenic diet therapy require frequent monitoring by their health-care team. They are seen by the ketogenic diet therapy team 1 month after going home and then every 3 to 6 months.
Check-ups will include measurements of weight and height, review of urine and blood tests, discussion of your child’s seizures and side effects of the diet, and a medical examination.
Between appointments, you will need to keep track of your child's seizure activity, urinary ketone levels, blood sugar levels, fluid intake and body weight. Record this information in a diary or your phone so that you can bring it with you to your child’s next clinic appointment.
Because your child is growing, the diet may need to be adjusted periodically to give them enough energy.
Some medications, including over-the-counter cough and cold medicines, intravenous (IV) fluids and even toothpaste, have sugar (carbohydrates) in them. The team will explain how to avoid using any medications with carbohydrates. Tell all doctors and pharmacists involved with your child’s care that your child is treated with a ketogenic diet therapy.
Discontinuing traditional/classic ketogenic diet therapy
If the diet has kept seizures well under control for several years, your child may be slowly taken off the ketogenic diet with guidance from their ketogenic diet therapy team. Alternatively, if the diet is not working or you find it too restrictive, the diet may be slowly discontinued, or your child’s ketogenic diet therapy team may suggest switching to a different diet therapy. If the diet continues to work well for your child’s seizures and your child has no negative side effects, the diet can be continued for longer. Some children will transition to adult health care with the ketogenic diet therapy.
All ketogenic diet therapies are usually stopped slowly over a 3- to 6-month period, during which protein and carbohydrates are gradually increased and fat is reduced. Your child's ketogenic diet therapy team will work with you to discontinue the diet.