 The ketogenic diet is a mainstream therapy that does not use pharmaceutical drugs , which was developed to reproduce the success and remove the limitations of the non @-@ mainstream use of fasting to treat epilepsy . Although popular in the 1920s and 30s , it was largely abandoned in favour of new anticonvulsant drugs . Most individuals with epilepsy can successfully control their seizures with medication . However , 20 – 30 % fail to achieve such control despite trying a number of different drugs . For this group , and for children in particular , the diet has once again found a role in epilepsy management . 
