Epilepsy & Seizures Support Group
Epilepsy (often referred to as a seizure disorder) is a chronic neurological condition characterized by recurrent unprovoked seizures. It is commonly controlled with medication, although surgical methods are used as well. Seizures (or convulsions) are temporary abnormal electrophysiologic phenomena of the brain, resulting in abnormal synchronization of electrical neuronal...
Poor diet can also bring on seizures, but mosts seizures have different affect on you, in other words there would be more symptoms than just blacking out.
Check out this site: http://www.emedicinehealth.com/fainting/page3_em.htm