There are four main dietary therapies used in the treatment of epilepsy: the Ketogenic Diet, Medium Chain Triglyceride Diet, the Modified Atkins Diet, and the Low Glycemic Index Diet.
The most commonly used is the Ketogenic Diet. The Ketogenic Diet is a nonpharmacological therapy for epilepsy that has been proven to effective in multiple studies. It uses a very high fat to low carbohydrate/protein ratio to induce a state of high ketones (which are produced by the body in a fasting state) that may reduce seizures. Although we do not know exactly how the diet works, we know that up to 10-20% of individuals will become seizure-free and overall, up to 2/3 of individuals will have >50% reduction in seizures. It is the treatment of choice for certain conditions such as Glucose-Transporter 1 Deficiency and Pyruvate Dehydrogenase Deficiency and is very effective in certain epilepsies such as Doose Syndrome, infantile spasms, and myoclonic epilepsies. In addition to seizure reduction, many individuals are brighter on the diet and many individuals are able to reduce antiseizure medications while on the diet.
The Ketogenic Diet must be strictly adhered to or it is not effective. The diet must not be started without expert supervision. It is critical that patients are followed by a team including a dietician, nurse, and physician to monitor adequate intake and potential side effects. There will be an initial orientation period (which may be done as an in-patient or as an out-patient depending on the center). Following this, patients are then followed by the team closely and with regular appointments and bloodwork. Potential side effects may include initial nausea during the initiation of the diet, constipation, kidney stones, nutritional deficiencies, and decreased bone density. Many of these possible side effects are minimized with supplements. Typically, ratios of 3:1 or 4:1 (grams of fat:grams of carbohydrate and protein) are used but lower ratios may be prescribed on an individual basis. The diet is usually taken for a 3 month trial period and if effective, may be used for 1-3 years although longer periods have been used safely.
The other diets are variations of dietary therapy with the main differences being the content. The Medium Chain Triglyceride Diet uses medium chain triglyceride oil to induce ketosis and allows more carbohydrate and protein allowance with similar efficacy of seizure reduction. The Modified Atkins Diet uses a 1:1 ratio and is more flexible with food choices (easier for adolescents and adults) while the Low Glycemic Index Diet uses low glycemic index carbohydrates and thus also offers more flexibility on food choices. Both the Modified Atkins Diet and Low Glycemic Index Diet offer more flexibility and variety in intake but in studies show less of an effect on seizure reduction.
The centers in Canada offering specialized dietary therapies can be found HERE.More information may be obtained from The Charlie Foundation.