Purpose: The ketogenic diet has well-established short- and long-term outcomes for children with intractable epilepsy, but only for those actively receiving it. However, no information exists about its long-term effects years after it has been discontinued.
Methods: Living subjects were identified who were treated at the Johns Hopkins Hospital with the ketogenic diet from November 1993 to December 2008 for ≥1 month, and had discontinued it ≥6 months prior to this study. Of 530 patients who were eligible, 254 were successfully contacted by phone or e-mail with a survey and request for laboratory studies.
Results: Questionnaires were completed by 101 patients, with a median current age of 13 years (range 2–26 years). Median time since discontinuing the ketogenic diet was 6 years (range 0.8–14 years). Few (8%) still preferred to eat high fat foods. In comparison to the 52% responder rate (>50% seizure reduction) at ketogenic diet discontinuation, 79% were now similarly improved (p = 0.0001). Ninety-six percent would recommend the ketogenic diet to others, yet only 54% would have started it before trying anticonvulsants. Lipids were normal (mean total cholesterol 158 mg/dl), despite most being abnormal while on the ketogenic diet. The mean Z scores for those younger than age 18 years were −1.28 for height and −0.79 for weight. In those 18 years of age or older, the mean body mass index (BMI) was 22.2.
Discussion: This is the first study to report on the long-term effects of the ketogenic diet after discontinuation. The majority of subjects are currently doing well with regard to health and seizure control.