Research Article| Volume 144, 109234, July 2023

Difficulties in the implementation of the ketogenic diet in adult patients with refractory epilepsy


      • Ketogenic diet therapies (KDT) are an essential treatment option for drug-resistant epilepsy in adult patients.
      • The application of KDT among adult patients with refractory epilepsy is challenging due to multi-factorial reasons.
      • Developing strategies to enhance compliance might significantly increase the number of patients who could benefit from this treatment.



      Ketogenic diet therapies (KDT) are appropriate therapeutic options for pediatric and adult patients with intractable epilepsy. The application of KDT among adult patients with refractory epilepsy is limited compared to children for several reasons, including poor compliance. We present the significant reasons for the lack of adherence to KDT in our adult patients with intractable epilepsy.


      This study was conducted retrospectively in adult patients with drug-resistant epilepsy who were offered and accepted to implement KDT between 2014 and 2021. Demographic and clinical data were collected via electronic health records. The eventual outcome of KDT results was obtained from the consultant dietitian. The prevalence and reasons for the failure to implement KDT were investigated. We also obtained detailed information about patients who successfully applied the KDT.


      A total of 33 patients (18F; median age 28) who were offered and accepted to implement KDT were included. Baseline seizure frequency was >4 per week in 49%, and more than half of the patients used >3 anti-seizure medications (ASM). Epilepsy types were temporal in 10 (30%), extratemporal in 10 (30%), generalized in 6 (18%), and unclassified in 7 (22%) patients. Only 3 patients (9%) were able to maintain KDT in the long term. One of them (33%) benefited from this therapy. In the remaining 30 patients, the reasons for failure were inability to contact the dietitian in 5, failure to apply KDT for a particular reason in 7, inappropriate blood test results or any medical/surgical comorbidities in 6, improvement in seizure burden due to change in ASM in 5, still insufficient knowledge of KDT in 3, unresponsiveness to diet due to incorrect implementation in 1 and unidentified reasons in 3 patients.


      A significant percentage of adult patients with refractory seizures failed to use KDT in our study (91%). Strategies to improve compliance and minimize the side effects might increase the number of drug-refractory epilepsy patients who could benefit from this therapy.



      ASM (Anti-seizure medications), cKDT (Classic ketogenic diet therapy), DRIs (Dietary Reference Intakes), GABA (γ-aminobutyric acid), IQR (Interquartile range), KD (Ketogenic diet), KDT (Ketogenic diet therapies), LGIT (Low glycemic index treatment), MAD (Modified Atkins diet), MCT (Medium-chain triglyceride), WHO (World Health Organization)
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