What does the ketogenic diet consist of?
The primary source of calories (~80-90% of diet) is fat: vegetable oils, butter, mayonnaise and heavy cream. Carbohydrates are very limited on the diet; carbohydrate sources include non-starchy vegetables and small amounts of fruit. Grains are eliminated and small amounts of dairy may be incorporated depending on the individual’s diet prescription. The diet provides adequate protein to support growth and maintenance.
What are the differences between the diet therapies?
The classic ketogenic diet is the most established and researched form of diet therapy. It is the strongest and most precise but also the least flexible of diet therapies. All foods must be carefully prepared and weighed on a gram scale using recipes created by a ketogenic dietitian. The classic ketogenic diet consists of a ratio in grams of fat to non-fat nutrients (protein and carbohydrates combined). Ratios range from 4:1 to 1:1. Children are admitted to the hospital to initiate the classic ketogenic diet at UCLA; admissions typically last ~4-5 days.
The modified Atkins diet (MAD) is a more flexible version of the classic ketogenic diet that is popular amongst adolescents and adults as it allows patients more freedom in food choice, meal timing and portion sizes. The diet therapy team educates patients during an outpatient teaching session, which includes individualized meal planning and how to use household measures (e.g. measuring cups and spoons) to prepare meals. At UCLA, a patient must be at least 5 years old to be a candidate for the MAD diet.
Low Glycemic Index Treatment (LGIT) is an alternative dietary treatment, which is less commonly used and not intended to promote ketosis. On LGIT, patients limit carbohydrate intake to ~40-60 grams daily with an emphasis on complex carbohydrates. Fat makes up ~60% of total calories and protein accounts for ~30%.
Are there specific conditions that respond well to diet therapy?
While diet therapy is considered a broad-spectrum treatment, there are specific epilepsy syndromes that often respond well including:
- Glucose Transporter (GLUT-1) Deficiency
- Pyruvate Dehydrogenase Deficiency
- Myoclonic-Astatic Epilepsy (also known as Doose syndrome)
- Dravet Syndrome
Is the ketogenic diet healthy?
The diet alone is not nutritionally adequate. Patients are prescribed special vitamin and mineral supplements to prevent any nutritional deficiencies. The dietitian carefully monitors growth in pediatric patients and weight in adult patients. We work closely with our patients to support the goal of balancing seizure control with optimizing nutritional quality and palatability of the diet therapy.
How long are patients typically on diet therapy?
If the diet is effective in improving seizure control, it is generally used for several years. When and how to taper diet therapy is determined on an individual basis in consultation with the primary neurologist and the diet therapy team. If diet therapy is not beneficial, it will be discontinued within a few months. At UCLA, we recommend a trial period of at least 3 months in order to accurately evaluate the diet’s impact on seizure control and optimize nutritional ketosis.
How are patients supervised by the diet therapy team?
Patients follow up in diet therapy clinic 1 month after initiating diet therapy, 2 months after the first follow-up appointment and every 3 months thereafter. Diet surveillance labs (blood and urine) are obtained prior to every clinic visit. The diet team reviews the labs and makes necessary adjustments to the diet therapy prescription and/or supplements.
What happens if a patient “cheats” while on diet therapy?
Ketogenic diet therapy should be treated like a medication. If a patient “cheats” on the diet by consuming foods or beverages that are contraindicated on the diet (e.g. high-carbohydrate foods like sweets or juice or excess quantities of certain foods), the patient is at an increased risk for seizures. The reaction is similar to missing a dose of the patient’s antiseizure medications and could result in a medical emergency.
Should patients change their eating habits before starting diet therapy?
Patients must meet their daily fluid requirements with non-caloric beverages (ideally, water) prior to initiating diet therapy. The dietitian calculates the patient’s fluid goal during the initial assessment in diet therapy clinic. Maintaining adequate hydration during diet therapy helps prevent and manage many of the side effects.
Additionally, we recommend patients eliminate packaged, processed foods and transition to a Real Foods Diet (insert link to Tips for Eating Healthy with Epilepsy Handout) in preparation for diet therapy.
Is the ketogenic diet used in patients who have feeding tubes?
Patients with feeding tubes are candidates for ketogenic diet therapy. There are specialized ketogenic formulas, and the dietitian will create a formula recipe and regimen. Patients who are unable to tolerate commercial formulas may be candidates for home-blenderized ketogenic formulas pending approval by the diet therapy team.