The ketogenic diet has been around in the medical literature for well over 70 years. It was replaced when the modern anti-convulsants became available, even though it has a very good success rate at controlling seizures. In some cases it is actually better than drugs at controlling seizures.
Most kids can stay on the diet two years, get off it and never have another seizure again.
The diet works best in children under ten. They are less likely to cheat and young children can maintain ketosis better than adults or older children. The diet mimics the effects of starvation. Surprisingly, children on the diet remain small and thin. There are no associated heart problems, since the fat is all burned up and not deposited.