Ketogenic Diet

A ketogenic diet consists of high fat, sufficient protein and low carbohydrate. It mimics a majority of the biochemical changes related to a lengthy period of starvation. It was initially developed in the 1900s and used successfully to treat seizures in children. This diet was all but forgotten with the development of anticonvulsant medicines. This diet has since been ‘rediscovered’ and is being widely used.

Diet History

Many clinical papers from the early 1900s highlighted that about a third of children on this ‘ketogenic diet’ were enabled to keep their seizures under control; a third were helped substantially to improve their siezure control, with a third hardly benefiting from the diet.

The biochemical effects of fasting can be replicated by being on a diet high in fat, however, containing insufficient carbohydrate to completely ‘burn’ the fats. The ‘ash’ from the incompletely burned fat is comprised of ketones in the blood.

When phenytoin was discovered in 1938, attention moved away from the ketogenic dietas new anticonvulsant drugs were developed. Thus the ketogenic diet was used less and less, as well as less successfully with fewer dieticians trained in the finesse of such a diet.

When a difficult-to-control child was treated successfully in 1994, the ketogenic diet gained a lot of good publicity and there was a re-ignition of interest in this diet particularlyin America .

What Does the Ketogenic Diet Comprise?

This diet is a high fat, enough protein, low carb diet, meticulously calculated for each child. Calorie intake is restricted and is dependent on the age as well as the level of activity of the child. Should the calorie intake have been calculated accurately, the child should not lose nor gain weight. The child ought to grow at a rate normal for his/her height and ideal weight. Should the child be overweight, the child is given limited calories until the ideal body weight is reached.

This diet provides about 90% of the child’s calories as fat, one gram per kilogram of body weight as protein, with little carbohydrate intake. This low carb diet has to be supplemented with calcium and vitamins.

How Does the Diet Work?

This diet replicates various metabolic effects of starvation. In starvation, the body initially uses its glucose and glycogen store, then it starts to burn stored body fat. When insufficient glucose is available, body fats cannot be burned and ketone bodies are left as residue. The ketogenic diet offers the body exogenous fats (fat external to the body) to burn. However, it restricts available carbohydrates to ensure that ketone bodies build up. It appears it is this high level of ketones that suppresses seizures.

So What Do Children on A Ketogenic Diet Eat?

Children on such a diet are allowed to eat set, meticulously calculated meals. As portions are slight, ketosis quashes appetite and quenches thirst. Given a short period of time adjusting to this diet, children rarely get hungry.

Many people may think such diets are not appetising. However, meals on this dietcan be surprisingly tasty.

A normal breakfast could be a mushroom omelette, several bacon slices and hot chocolate with 36% cream. Lunch could be celery stalks with peanut butter, lettuce, mayonnaise, tomato, with a caffeine-free dietdrink to wash it all down. Dinner could be a specifically weighed portion of hot dog, ketchup, mustard, lettuce, mayonnaise, as well as a whipped cream sundae with strawberries and a diet drink.

Is this Diet Effective?

Older studies document the effectiveness of this diet. It remains as effective today with children who have difficult-to-control seizures as it did in yesteryear, despite the use of anticonvulsants.

The 1998 Johns Hopkins study (Source: Pediatrics December 1998) assessed the effectiveness and tolerability of this diet amongst 150 children.

The children studied had 400 plus seizures a month prior to going on the ketogenic diet. They had also tried six or more types of anticonvulsants. The following were the outcomes:

71% of the children who started the diet stayed on it for six months plus, with more than 50% remaining on this diet for a year. The diet proved effective in reducing seizures and it was well tolerated. The most frequent reason for stopping the diet was that it not effective enough to warrant the strict dietary restrictions. The diet was as effective across age ranges and with children of varying seizure types.

Who Is this Diet For?

This diet is a therapy for children suffering from difficult-to-control epilepsy. Difficult-to-control epilepsy is defined as having more than two seizures a week, in spite of the use of two plus anticonvulsant medicines. Adequate investigation of the ketogenic diet has not been undertaken amongst children under a year old nor adults.

Parents considering this diet to be appropriate for their child need to consult their GP as the first port of call. This diet ought never be attempted without strict medical supervision.

Can my Child Stop taking Anticonvulsants?

The aim of the diet is ensure all children going on this diet become seizure and medication free. However, this is not always possible. Some patients do, over time, discontinue medications when on this diet. Nonetheless, some do continue having seizures and require a certain amount of continued medication.

Can My Child Be Given Any Other medications on this Diet?

It is vital to avoid anything with carbohydrates in it. So it is necessary to read labels meticulously; any substance ending with -ol or –ose has carbohydrates in it.

Even using suntan lotion which has a base containing sorbitol can be absorbed through the skin, reducing the ketone level, resulting in seizures.

What is the Length of Time Children Typically Stay on this Diet?

Children whose seizures become totally controlled on this diet often discontinue this diet after a seizure-free period of two years. Others are on this diet as long as it proves effective. Should the diet be stopped, or the ratio decreased, with seizures returning, then the child can do back on the diet or go back to taking medication.

How Does this Diet work?

It seems that the high fat intake along with carbohydrate and calorie restriction result in ketosis. The current standard of care requires that the urine remains 4+ (160-180mml) for ketones. Recent research highlights that serum ketone levels could be far more important than those in urine.

4+ urine is fine for seizure control, however, it may not be sufficient for optimum control; calories need thus to be further curtailed or the ratio of fat to protein and carbohydrate may need to be increased.

How the ketone bodies suppress seizures is not known and is presently an area under investigation.