The ketogenic diet is a therapeutic diet used in the management of some health conditions, such as drug-resistant epilepsy. There are several different variants on the diet that can be applied in different circumstances.
In addition to the different diets outlines below, the ketogenic diet can be administered via gastrostomy tube and there are many other variants in different regions of the world.
The classic ketogenic diet requires the involvement of a dietitian, who will make dietary recommendations based on individual characteristics, such as age, weight, physical activity culture and food preferences.
The energy requirements for a child following the ketogenic diet is typically 10-20% less that recommended daily amounts, due to the high-density energy in the fats that make up the majority of the diet. The ratio of fat to carbohydrates and protein combined is approximately 4:1, but may be lower for young or obese children.
A typical meal on the classic ketogenic diet consists of heavy whipping cream, protein rich food such as meat, low-carbohydrate vegetable and fat such as butter or vegetable oil. Fruit and vegetable that are high in carbohydrates, such as bananas, potatoes, peas and corn are not included in the diet.
It is worth noting that the classic ketogenic diet is not balanced as it includes very little portions of fruits, vegetables, cereals and sources of calcium. As a result of this, supplementation is required to compensate for this, which usually include a multivitamin and calcium and vitamin D supplements.
Medium-Chain Triglyceride (MCT) Variant
Medium-chain triglycerides generate more ketones per unit of energy than the long-chain triglycerides that are present in normal dietary fat. Therefore, a diet rich in MCTs can have a lower proportion of fat and more protein and carbohydrates while still producing the same effect. This is preferable as individuals can have greater variety in their diet and portion sizes can be slightly increased.
Caution in using high quantities of MCT oil must be practiced, as adverse effects such as abdominal cramping, diarrhea and vomiting have been reported in high doses. Approximately 45% MCT oil is considered to be a good balance of response and risk of side effects.
Modified Atkins Diet (MAD)
This variant is based on the Atkins diet and stems from the discovery that the induction phase of the Atkins diet helped to control epileptic seizure in 2003. The diet was modified with the aim to extend the induction phase, which involved higher fat intake that a normal, balanced diet.
This differs from the classic diet in that the fat to protein and carbohydrate ratio is approximately 1:1 and children following this diet generally require less support from a dietician. Dietary supplements are still required, however, to ensure children receive essential vitamins and mineral.
Low Glycemic Index Treatment (LGIT)
This variant is a less limiting regimen that is based on the stabilization of blood glucose levels. The concept that carbohydrate restriction and increased fat consumption in the diet is thought to be involved in the mechanism of action of the ketogenic diet is extrapolated to reduce seizure by controlling blood glucose levels.
Intake of fat remains high, with about 60% of calorie intake coming from fats, but more carbohydrates are allowed to be consumed that in other variants, such as the classic or Atkins diet. The restriction is based on the type of carbohydrates, which should have a glycemic index lower than 50.