Level 2: Mid-level evidence
A recent trial evaluated the efficacy of the ketogenic diet for the treatment of seizures in children (Lancet Neurol. 2008;7:500-506). Children aged 2-16 years (N=145) with at least seven seizures per week and no response to at least two anti-epileptic drugs were randomized to the ketogenic diet vs. no change in treatment for three months. Neither family nor investigators were blinded to the treatment assignment. Data for 103 children (71%) were available for analysis; intention-to-treat analysis was reported assuming there was no substantial seizure reduction in children who dropped out.
Comparing the ketogenic diet vs. no change in treatment, the mean change in seizure frequency from baseline was -38% vs. +36.9% (P <.0001). More patients on the ketogenic diet had a >50% reduction in seizures (38.4% vs. 5.6%, P <.0001, NNT 3). Using a more aggressive outcome measure, more patients on the ketogenic diet had a >90% reduction in seizures, but this did not quite reach statistical significance (6.8% vs. 0, P =.0582).