Ketogenic Diet Therapies for Adults Presentation by Alex Printis, Registered Dietitian
What is the Ketogenic Diet?
It is a therapeutic diet that is sufficiently high in fat and low in protein and carbohydrate that when eaten, a state of ketosis is produced. It is prescribed for children who have seizures and is generally recommended for seizure control when anticonvulsant medications have failed.
Who Discovered the Diet?
Fasting and the ketosis this produced, has been recognized since biblical times as having a beneficial effect on seizure control. In 1921, Wilder introduced the modern ketogenic diet in an attempt to reproduce the metabolic affects of starvation. It has been used since then, but probably less frequently since the early 1950’s when more effective anti-convulsants became available.
Who can be Helped by the Diet and How Much?
Traditionally, the diet has been used in young children, between the ages of 2 and 6 years old with myoclonic atomic and tonic-clonic seizures. It is often difficult to begin and maintain ketosis in children under a year of age and older children may rebel at the food restrictions. Some studies indicate that the diet is not as effective in partial or focal seizures and in absence or petit mal types of seizures. However, when traditional medications have not been effective or if they produce unwanted side effects the ketogenic diet should be considered as an alternative treatment. We will consider a trial of the diet in older individuals since we have tried the diet in teens and young adults with similar results as the younger children.
How Does the Diet Work?
No one is certain exactly how the diet works. Originally, it was thought to be related to the ketosis that fat metabolism produce. Ketones are the end products of fat breakdowns and circulate in the blood once the diet has been initiated. Our body normally burns glucose (sugar) for energy, and can store up to one day’s supply. After a one-day fast most of the glucose in the blood is used up this causes the body to burn stored fat for energy, resulting in ketosis. The ketogenic diet is high in fat, which the body converts to ketones and used for energy by the brain and other body cells rather than glucose. The diet also limits total fluids to promote a state of slight dehydration, which may also reduce seizures. Children may also become too ketotic and/or develop hypoglycemia (low blood sugar), which may require additional monitoring.
What is the Diet All About?
Ketosis is produced by eating foods that are ketogenic (fats), and limiting foods that are anti-ketogenic (carbohydrates and proteins). Dietitians calculate haw many calories a child needs for energy and minimal growth. The calorie allowance is approximately 75% of RDA for the child’s age. (Ages 1-3=75 calories/kilogram body weight; ages 4-6-68 calories/kilogram; and ages 7-10=60 calories/kilogram.) To maintain the desired ketosis, the ketogenic diet is described in terms of a ration of fat to carbohydrates + protein. For example, a 4:1 ration means that for every 1 gram of carbohydrate protein there should be 4 grams of fat, or 4 times as much fat as carbohydrates and proteins. This means that for every 100 calories, 80 calories will come from fat and 20 calories will come from protein carbohydrate. The dietitian develops meal plans that provide the calories in the appropriate ration and it is imperative that you maintain the diet exactly as planned. Each meal plan gives the exact number of grams for each food item that is allowed in that meal. The food is weighed by using a gram scale. The allowed foods on the diet are limited but can include some small amounts of fruits and vegetables. The diet virtually eliminates sugar, starches, grain and bread products. The diet must be followed rigidly. Even very small amounts of extra carbohydrate like a bite of a cookie or cracker may cancel the whole effect the diet is trying to accomplish. Fluids are usually limited to about 1 ounce per pound per day.
Does the Diet Provide Adequate Nutrition?
The diet significantly limits dairy products, grains, fruits and vegetables. Therefore it is not a nutritionally adequate diet and daily vitamin and mineral supplements are necessary. In addition many anticonvulsant medications affect nutritional status and may require additional supplements. Many parents become dismayed that so many supplements are added to their regimen when their ultimate goal is to decrease medication administration. But it is important to maintain adequate vitamins and minerals like calcium for good bone growth and maintenance of general health.
What are the Risks and Benefits of the Diet?
The obvious benefit of the diet is the potential for seizure control. Sometimes seizures are controlled as soon as the child becomes ketotic, but this effect may not be seen for as long as a month after it is discontinued. This could lead to a child who has seizure control without any of the side effects of medication (sedation, cognitive impairment, behaviour changes, hyperplasia of the gums, liver and blood abnormalities). The child may not grow as rapidly as before the diet and he/she is monitored for protein gain. If your child needs to stay on the diet for longer than 2 years the amount of calories are adjusted to allow for minimal growth. Laboratory data is monitored monthly for cholesterol and lipids (fats), anticonvulsant levels and blood chemistries so that any signs of problems are detected early and treated. A few children have developed kidney stones this has been treated by increasing the amount of fluids allowed and by certain medications. Sometimes it is necessary to take the child off the diet if the stones cannot be controlled. The restriction of certain foods sometimes leads to behavioral problems and the family may decide to discontinue the diet for this reason. Many parents, however, note improved behavior. During an acute illness the diet may pose some increased risk for dehydration. This should be monitored carefully.
BC Children’s Hospital
At BC Children’s Hospital, the diet is offered to families whose children’s seizures are intractable, despite appropriate use of at least 2 different anticonvulsants. Referral Required.
BC Children’s Hospital – Neurosciences
The traditional way of starting the diet is to have the child admitted for a 24-72 hour fasting period then start the diet at the 4:1 ratio. The child will usually have a 5-7 day stay in the hospital. At the Children’s hospital the diet is initiated after the parent/caregiver attends the daylong educational class. The diet is started at a lower ratio (2:1) and the ratio is increased every 3-5 days depending on the age of the child. Ketosis is often without fasting, while at the 3:1 ratio however, it is seldom maintained and requires increases up to the 4:1 ratio for sustained ketosis. Phone consultations with the program nurse and dietitian may be frequent at the onset of the diet and continue as needed while on the diet. Clinic visits should be 3 and 6 months after the diet begins then as indicated by the physician.
Families should commit to follow the diet rigorously and precisely for a 6-month trial. When a good response is achieved, the diet is maintained for at least a period of two years. If your child is seizure free and off the other anti-convulsants the diet is then reduced to lower ratios each 6 months until back to a regular diet. Some children to go without seizures or the need of medications once the diet has been discontinued.
Recommended reading: The Ketogenic Diet, by John and Jennifer Freeman and Millicent Kelly, 3rd edition, ISBN 1-888799-39-0, available to borrow from the Family Resource Library at BC Children’s Hospital.
For more information about the Ketogenic diet program at BC Children’s Hospital, visit the The Neurological Care Centre’s website or contact the number listed below.
Phone: 604-875-2121
Fax: 604-875-2285
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