Nutrition Interventions for Children with Special Health Care Needs

Chapter 22 - Ketogenic Diet for Seizure Disorders
This chapter will focus on the traditional KD. The traditional KD is based on an exact
ratio of fat to combined protein and carbohydrate. For example, a 4:1 ratio would
have 4 grams of fat to every 1 gram of protein and carbohydrate combined. (1,4,7,8)
At the 4:1 ratio, fat contributes 90% of calories. Protein and calorie requirements are
established based on current DRI with the goal of meeting needs for growth. Heavy
whipping cream is usually the foundation of all meal plans, followed by butter, oil,
and mayonnaise. Fluid restriction does not play a role in seizure control, and is no
longer recommended (8,9). Vitamins and minerals as well as fiber are inadequate in
the KD, and must be supplemented (6,8).
The diet can be implemented on an outpatient or inpatient basis (6). The Johns
Hopkins inpatient protocol for initiating and maintaining the KD has been gradually
modified at Johns Hopkins and other centers, and is continually evolving. Some
centers observe a fasting protocol of approximately 24 hours. Others observe an
overnight fast with no food consumption after midnight (3). Extended fasting does
not produce better results.
Two approaches are observed with respect to starting the diet. The first approach
starts at a lower ratio with full calories, such as a 2:1 ratio. The ratio is to be
increased based on patients’ tolerance.. The second approach is to provide the diet
at a set ratio, such as a 3:1 or 4:1 ratio, but starting with 1/3rd calories, increasing
daily until full calories are tolerated.
The outpatient approach does not involve fasting. The diet can be started at a lower
ratio such as a 2:1 ratio then progressed in 3-5 day increments to a 3:1 ratio then
4:1 ratio. Hypoglycemia, acidosis, nausea, vomiting and lethargy can be minimized
or avoided by implementing the diet according to this protocol.
The KD is particularly effective in controlling absence, atonic, myoclonic seizures
and infantile spasms. However, it may be tried as a therapy with any child who has
refractory seizures (10). The diet is usually prescribed for children over the age of
one year. Children younger than one year of age have more difficulty maintaining
ketosis and experience a higher incidence of hypoglycemia. However, it is offered
as a therapy at Johns Hopkins in infants with infantile spasms. Infants should
be assessed on an individual basis to determine if KD therapy is appropriate.
Historically, the diet has been felt to be most effective in children ages 2 to 5 years
of age. Children and young adults alike have had success in controlling their seizures
with the KD (9). The diet will control seizures in approximately one-third of children
who have been unable to control them with medications. Of the remaining number
of children, one-half will have some degree of improvement in their seizures and/
or anticonvulsant medications reduced (2,4,8,11,14). Because of issues of noncompliance,
older children may have more difficulty maintaining adequate ketosis
248 Nutrition Interventions for Children With Special Health Care Needs