The number of seizures in children who were put on the "ketogenic" diet, which features high levels of fat, low levels of carbohydrates and controlled protein intake, fell by a third, where previously they had suffered episodes every day even with medication.
Writing in the latest issue of the Lancet Neurology, the researchers said they are not sure how it works but it appears ketones, produced from the breakdown of fat, help to alleviate seizures.
In the trial, 145 British children aged between two and 16 who had drug-resistant epilepsy and failed to respond to treatment with at least two anti-epileptic drugs were given the special diet.
According to BBC reports, the number of seizures in the children on the diet fell to two-thirds of what they had been, but remained unchanged in those who were on a normal diet.
Experts believe that the regimen's high fat and restricted carbohydrate content mimics the biochemical response to starvation, when compounds called ketone bodies (rather than sugar) provide the main source of energy for the brain.
Researchers from the University College London, however, say that information is needed about the long-term effects of the ketogenic diet, such as changes in blood fat concentrations and ketosis. Experts also say that if the children's epilepsy is easily controlled on one medication then they should follow normal diet regime.
