Duration of the diet
(J. Klepper, Aschaffenburg; updated 01.2007)
The ketogenic diet needs to be continued at least for three months maintaining adequate ketosis to be evaluated. If there is no significant reduction of seizure frequency or duration, the diet can be discontinued within days.
In intractable childhood epilepsy, an effective ketogenic diet should be reevaluated and can possibly be discontinued after 2-3 years – often seizure control is maintained despite the return to a regular diet. Discontinuation can be achieved by gradually reducing the ratio of fat to non-fat (e.g. from 4:1 to 3:1 to 2:1) every other month.
In GLUT1 deficiency syndrome, the duration of the ketogenic diet is not yet established - as the developing brain needs 3-4 times the energy of the adult brain, the diet should at least be maintained into adolescence. In patients with pyruvate dehydrogenase deficiency the ketogenic diet should not be discontinued.