Use of cooking oils in a 2:1 ratio classical ketogenic diet for intractable pediatric epilepsy: Long-term effectiveness and tolerability

In many parts of eastern Asia, rice is a dietary staple and therefore the ketogenic diet (KD) can be difficult to administer. The aim of this study was to assess the long-term effectiveness and tolerability of the classical KD using a 2:1 ratio of fat to protein plus net carbohydrates, which is lower than the ratios of 3:1 or 4:1 typically used in classical KD for intractable pediatric epilepsy.

In this prospective study, cooking oils rich in polyunsaturated fatty acid or omega 3 fatty acids, such as olive oil, camellia oil, linseed oil, grape seed oil, and/or perilla oil were used to formulate a classical KD with a 2:1 ratio for infants and children diagnosed with medically intractable epilepsy from April 2002 to April 2018. Subjects received the diet for at least 3 months. The efficacy of the diet was analyzed at 3, 6, 12, and 24 months, and at > 3 years. Tolerability during the period of diet administration was analyzed by medical records and parental reports.

Sixty-three subjects, 29 males and 34 females, were enrolled from April 2002 to April 2018. The median age at diet initiation was 2 years 11 months. The median duration of adherence to the diet was 1 year 2 months. The seizure-free rate was 14%, 16%, 17%, 14%, and 14% at 3, 6, 12, and 24 months', and at > 3 years' follow-up, respectively. A greater than 50% seizure reduction was achieved in 52%, 43%, 40%, 33%, and 30% of subjects at each time point. The dietary compliance rate was 100%, 70%, 60%, 35%, and 27% at each follow-up time point. The reasons for discontinuation of the KD were the lack of further improvement in seizure frequency, seizure freedom achieved, food refusal, hyperlipidemia, and poor parental compliance in 38%, 11%, 5%, 2%, and 2% of subjects, respectively. Gastrointestinal discomfort was the most common adverse effect.

The classical KD with a 2:1 ratio showed clinical effectiveness and tolerability in intractable pediatric epilepsy after long-term follow-up.