2.2.4 The low glycemic index treatment (LGIT) diet

2.2 Conventional ketogenic diets in epilepsy

Epilepsy - Advances in Diagnosis and Therapy

hydrate, described by weight or by calorie intake.

2.2.2 The medium-chain triglyceride (MCT) diet

2.2.3 The modified Atkins diet (MAD)

2.2.1 The classic ketogenic diet (CKD)

by weight [23].

index treatment.

Table 2.

150

To date, four major, "conventional" ketogenic diets are supported by published evidence in the treatment of children and adults with epilepsy (Table 2) [2, 3]. The primary difference between each diet lies in the ratio of fat to protein plus carbo-

Created by Wilder in the 1920s [1], the CKD is the oldest of all ketogenic diet therapies and in its purest form consists of 80% fat by weight (roughly equivalent to 90% fat by caloric intake), translating to a 4:1 ratio of fat to protein plus carbohydrate, although a 3:1 ratio or lower can often be used [2]. In the CKD, the fat source consists predominantly of long-chain fatty acids, obtained from standard foods.

In an effort to make the ketogenic diet more palatable, the MCT diet was introduced in the 1970s [22]. In its original form, the MCT diet is 60% fat by weight (roughly 75% fat by caloric intake), with fat sourced from MCT oils. Since mediumchain fatty acids yield more ketones per kilocalorie compared to long-chain fatty acids, the MCT diet allows for a lower overall fat intake, and a greater intake of protein and carbohydrate, compared to the CKD. A number of patients are prone to gastrointestinal side-effects on this diet, so a modified MCT diet was created in the 1980s, consisting of 30% medium-chain fatty acids plus 30% long-chain fatty acids

In the early 2000s, the MAD was shown to be effective in treating epilepsy [24].

The MAD is approximately 50% fat by weight (65–70% fat by caloric intake),

Protein 12% Protein 6% Carbohydrate 8% Carbohydrate 4%

Protein 16% Protein 10% Carbohydrate 24% Carbohydrate 15%

Protein 35% Protein 25–30% Carbohydrate 15% Carbohydrate 5%

Protein 45% Protein 30% Carbohydrate 15% Carbohydrate 10% CKD = classic ketogenic diet; MCT = medium-chain triglyceride; MAD = modified Atkins diet; LGIT = low glycemic

CKD Fat 80% Fat 90%

MCT diet Fat 60% Fat 75%

MAD Fat 50% Fat 65–70%

LGIT diet Fat 40% Fat 60%

Conventional ketogenic diets supported by published evidence in treating epilepsy.

Ketogenic diet Macronutrient ratio (by weight) Macronutrient ratio (by calorie intake)

The LGIT, roughly 40% fat by weight (60% fat by caloric intake), was introduced in the early 2000s as a treatment for epilepsy [25]. The design of the LGIT was based on the hypothesis that stable glucose levels contribute to the seizure control conferred by ketogenic diets. The LGIT allows for relatively liberal levels of protein and carbohydrate intake, emphasizing carbohydrates with glycemic indices less than 50.
