what is the ketogenic diet?

It is a complementary method of treatment sometimes prescribed to children whose epilepsy remains poorly controlled despite the regular intake of prescribed medication. It is a high fat diet {90% of calorie requirement}, with adequate protein {1 gram per kg of body weight} and low carbohydrate intake. Calories and fluids are limited and depend on the age and activity of the child. The diet is designed to mimic many of the biochemical changes associated with prolonged starvation and must be supplemented with vitamins.

the background of the ketogenic diet

The diet was first developed and administered in the 1920’s when scientific papers advertised the beneficial effects of prolonged fasting for children whose epilepsy remained uncontrolled by the few medications then available. Fasting along with drinking water for just 10-20 days could result in seizure control for a prolonged period of time. Clinical papers of that era reported approximately one third of children on the Ketogenic diet has their seizures controlled, one third experienced a substantial improvement in seizure control, and the remainder derived no significant benefit.

what does the diet do?

The diet stimulates many of the metabolic effects of starvation. During starvation, the body first uses up its store of glucose, and then it begins to burn its stored body fat. If there is sufficient glucose, the fats cannot be completely burned and ‘ketone bodies’ are left as a residue of the incompletely burned fats.

The diet provides exogenous fats {from outside the body} fro the body to burn up, but available carbohydrates and glucose are limited. This leads to an increase in the level of ketones bodies in the blood. However it still remains unclear how this high level decreases, or sometimes completely controls seizures.

what do children on the diet actually eat?

The children only eat prescribed and carefully calculated meals. Portions are small, but the process of ketosis suppresses appetite and thirst, and, after a short period of adjustment, the children should not experience hunger.

are the children on the diet able to stop taking anti-epileptic medication?

This is the long-term aim. Some patients are able to gradually discontinue medication while on the diet, but unfortunately may children do not become seizure free and require continued medication.

do children gain weight on the diet?

Children should not gain weight as the number of calories is carefully tailored to the needs of the child. Children should only gain weight in proportion to the increase in height. Should the child become overweight, calories are limited until the ideal body weight is reached.

how successful is the ketogenic diet?

The effectiveness of the diet has been documented in many older studies. In a 1998 study, the effectiveness and tolerability of the diet were evaluated in 150 children. The children had tried on average 6 different anti-convulsants and averaged more than 400 seizures per month before the diet.

the results

· 48 [32%] experienced 90% control at 6 months and 41 [27%] at 12 month

· 29 [19%] experienced 50-90% control at 6 months and 30 [20%] at 12 months

· 29 [19%] experienced under 50% control at 6 months and 8 [5%] at 12 months

· 106 [71%] remained on the diet at 6 months and 83 [55%] at 12 months

When the diet was successful in decreasing seizures, it was in general well tolerated. The most common reason for discontinuing the diet was when it was insufficiently effective to warrant the dietary restrictions.

HOWEVER IT IS IMPORTANT TO REMEMBER THAT:

· This is a controversial therapy for children with difficult to control epilepsy.

· The Ketogenic diet should only be considered under the supervision of a physician and a dietician.

· No attempt should be made to change a child's diet without medical supervision.

· Parents who think that the diet may be an option for their child should consult their doctor.

further reading

‘The epilepsy Diet treatment - An introduction to the ketogenic diet’, By John M Freeman, Millicent T Kelly MD and Jennifer B Freeman {Demos Vermande, New York}