The ketogenic diet
The ketogenic diet is one that is high in fat and low in carbohydrates or
sugar and may be helpful in treating your child's seizures.
Normally, the brain uses glucose for energy. Most glucose is made from the
digestion of carbohydrate-rich foods. But in the ketogenic diet, the high
proportion of fat versus protein and carbohydrate causes the body to use fat
instead of carbohydrates (sugar or glucose) for energy. When fat is broken down,
ketone bodies are produced as a residue; ketones can have an anti-seizure effect
in the brain.
The fat in the diet comes mostly from 36% heavy cream, butter, margarine,
mayonnaise, and oil. Foods such as bread, rice, pasta, potatoes, milk, fruited
yogurt and sweets are not included in the ketogenic diet. It is important to
only eat the foods prescribed for the diet. Even a small amount of carbohydrate
can upset ketone production and therefore affect seizure control. Liquids
besides the heavy cream can include water, ice, or up to one calorie per day of
sugar-free decaffeinated diet soda, tea, and/or coffee. A few ounces of liquids
should be given every one to two hours.
The diet is calculated in terms of a ratio. Two examples of ketogenic ratios
are 4:1 or 3:1. For example, a 4:1 ratio means the diet has four grams of fat
for each gram of protein and carbohydrate combined. Ratios are determined by
your dietitian and physician according to the individual needs of your child.
Additionally, the ratio can be adjusted to achieve maximum seizure control. It
is important to eat all of the food at each meal to maintain the specific ratio
prescribed.
Is the diet nutritionally complete?
To help meet your child's nutritional needs while on the ketogenic diet,
supplements are necessary. Recommended supplements include a multivitamin called
Centrum Advanced Formula and calcium tablets by Nature Made or calcium capsules
by Watson called Cali-Mix (must be ordered by your pharmacist). These
supplements can be purchased at most grocery and drug stores. Additional
supplements may be recommended by your dietitian.
The diet has been known to work immediately, or it can
take several months. The first several months of the diet may involve
fine-tuning to meet individual needs. Most patients are on the ketogenic diet
for about two to three years. When it is necessary to end the diet, the ratio is
slowly decreased, and more protein and carbohydrate are allowed.
Begining the diet
The patient is usually admitted to the hospital for three to five days.
Fasting, which is initiated so the body starts to use fat for energy, usually
lasts for 24 to 36 hours or until your child begins to produce ketones. During
hospitalization your medical team carefully monitors urine ketones and blood
sugar levels. Once the diet is initiated, only a small amount of food is given.
This allows the body time to adjust to the high fat. The first three meals are
1/3 of the total diet. Meals four, five and six are 2/3 of the diet. Meal seven
is usually the first complete meal.
Each food item is weighed on a special scale that measures food in grams.
Since the diet is extremely high in fat the amount of food at each meal may seem
small. This is because fat has more calories than carbohydrate and protein. Your
child's diet will be monitored closely by the dietitian to ensure that your
child has enough calories to continue to grow and stay healthy.
Once your child is safely tolerating the full strength diet, discharge will
be considered.
Measuring ketones
Ketone levels are measured with ketone sticks -- small strips that are dipped
into the urine. Ketones are higher in the afternoon and evening and lower in the
morning. In the first few months on the diet, ketones should be checked twice
daily. The levels can be small, moderate or large. The larger the ketone level,
the better the potential for seizure control.
If your child is found to have small ketone levels while on ketogenic diet,
consult the dietitian to help find the possible causes. Ketones are typically
lower in the morning, and some patients' levels may decrease from levels that
are large in the afternoon or evening to moderate or even small amounts in the
morning. If children have seizures in the morning and ketones are small, the
diet ratio may be increased, and if necessary a later dinner meal or an evening
snack may be ordered. If ketone levels are found to be small at any time of day,
the child may be eating or drinking something that is not on the diet. If this
occurs, carbohydrates such as fruits or vegetables can be excluded from the next
two meals. Then ketone levels should be rechecked.