Ketogenic Diet

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The Ketogenic diet is designed for individuals who suffer from seizures. Many individuals with autism suffer from seizures, and this diet may help control that symptom. This diet began seventy years ago when doctors at Johns Hopkins Hospital gave patients high-fat, low-protein, and low-carbohydrate food in order to control their seizures. It has also been used to treat structural brain disorders such as microcephaly, hypoxic brain damage, prior strokes, and developmental abnormalities.

Despite the use of this diet in the treatment of seizure disorder since the 1920s and before, its exact mechanism is unknown. Research was largely discontinued when newer anti-epileptic drugs became available in the 1940s.

The Ketogenic Diet is used in children who do not respond to standard therapy or cannot tolerate the side effects produced by anti-epileptic drugs. The Ketogenic Diet is a high-fat (80 percent), low-carbohydrate diet that fundamentally changes the body’s metabolism from using glucose as a primary energy source to using fats. Ketones are a type of lipid, or fat, which provide energy for skeletal muscle, the heart, kidneys, and the brain.

The Ketogenic Diet is usually most effective in children 10 years old and younger. The diet is typically begun with a period of fasting for 12-24 hours. When a person’s body has no food for 24 hours it uses up all the stored glucose. With no more glucose to provide energy, the body begins to burn stored fat – a process called ketosis. The Ketogenic Diet keeps ketosis going.

Every meal includes exact amounts of fats, proteins, carbohydrates, and beverages, and only those foods listed for the diet can be eaten. Each meal has about four times as much fat as protein or carbohydrate. Meal plans serve small amounts of fruits or vegetables (carbohydrates) and meat, fish or chicken (protein) with lots and lots of fat (such as cream, butter, eggs, or mayonnaise), and no sugar. The amounts of food and liquid at each meal have to be carefully worked out and weighed for each person. Snacking is discouraged and sugars are not allowed.

A vitamin and mineral supplement must be given.

Advantages and Disadvantages

The Ketogenic Diet should be undertaken only with close medical supervision. Children must be monitored for growth and nutritional deficiencies. Common complications include poor growth and poor weight gain, hypercholestrolemia (high cholesterol), and constipation. It is prescribed only when both the child and the family are highly motivated.

The diet may be prescribed for 2 to 3 years.

It is said that adults may have problems maintaining essential nutrients and therefore may not benefit from the diet, but in-depth studies are rare and inconclusive. Many adults would not want to eat such a diet — most find it unpalatable — and find it very difficult to stick to. The Ketogenic Diet is both safe and effective, with rare side effects only when it is not strictly followed.

There is documentation of rare kidney stone formation, lowered immune functions, low blood sugar, and implication of increased serum lipid profile, which requires close monitoring. During the initial fast, your child’s blood sugar level should be checked every four to six hours. The level often falls, which may lead to hypoglycemia.

Treatment Outcome

When rigidly adhered to, the Ketogenic Diet may successfully control epilepsy in 30-50% of children with intractable seizures. Many others will experience a marked decrease in seizure frequency. Many will be able to return to a normal diet within 2 to 3 years, free of seizures or medication. The rest either do not respond at all or find it too hard to continue with the diet, either because of side effects or because they can’t tolerate the food.

Most people investigate this diet as a last resort. The diet can be unpalatable and demands a great commitment from the entire family for a considerable period of time. Most people who make it past the first month will stick with the diet until they can return to a normal diet.

In Ontario, the Ketogenic Diet is administered at the larger children’s hospitals and several clinics. Although this sounds promising, the diet shouldn’t be followed without the close supervision of a neurologist. The diet needs to be tailored precisely for each child, according to his or her age, height, and weight, and it must be carefully overseen by a knowledgeable professional.


“The Epilepsy Diet Treatment an Introduction to The Ketogenic Diet” by John M. Freeman, M.D., Millicent T. Kelly, R.D., L.D. & Jennifer B. Freeman.

Seizures and Epilepsy in Childhood: A Guide for Parents by John M. Freeman, et al.


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All information, data and material contained, presented or provided here is for general information purposes only and is not to be construed as reflecting the knowledge or opinions of Autism Canada, or as providing legal or medical advice. All treatment decisions should be made by the individual in consultation with a licensed health care provider.

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