Ketogenic Diet in Combination With Standard-of-care Radiation and Temozolomide for Patients With Glioblastoma

Inclusion Criteria: * Adults (age ≥ 18 years) * Newly or recently diagnosed glioblastoma. Patients may enroll in the study from the time of diagnosis (prior to the initiation of standard-of-care chemoradiation) up until the initiation of post-radiation adjuvant chemotherapy (typically approximately 3-4 weeks after the completion of radiation therapy). Overall, this provides a window of approximately 3 months from the time of diagnosis for patients to enroll in this study. No recurrent glioblastoma is allowed on trial. * Being seen for treatment of glioblastoma at Cedars-Sinai Medical Center. Note: Okay if patients receiving chemotherapy or radiation therapy at another facility * Patients on low and managed doses of steroids are permitted. Up to 8 mg dexamethasone or steroid equivalent. Exclusion Criteria: * Karnofsky Performance Status of \<70 as deemed by physician or equivalent * Body Mass Index of \<22 kg/m2 (rounded to nearest integer) * Patients with disorders that affect lipid metabolism such as pyruvate carboxylase deficiency, porphyria, primary carnitine deficiency, carnitine palmitoyltransferase I or II deficiency, carnitine translocase deficiency, Beta-Oxidation Defects * Medical comorbidities that in the opinion of the investigator limits the patient's ability to complete this study * Pregnant, nursing, or implanted with an intrauterine device (IUD) that is not MR compatible * Patients who are vegan or vegetarian will be excluded, as the ketogenic diet includes …