Glioma Modified Atkins-based Diet in Patients With Glioblastoma

Inclusion Criteria:

1. Patients must have a clinical and histopathologic diagnosis of GBM, have completed \>80% of prescribed concurrent radiation therapy and adjuvant temozolomide without CTCEA grade 3 or 4 toxicity, and be greater than 7 months from the time of completion of concurrent chemoradiotherapy.
2. Karnofsky performance status \>/= 60.
3. Patients must be at least 18 years of age.
4. Patients must be eligible to undergo a ketogenic or Atkins based diet according to baseline body mass index (BMI, see exclusion criteria), comorbid medical conditions (see exclusion criteria), and baseline laboratory assessment (see exclusion criteria).
5. Patients must be of appropriate mental capacities with sufficient social support so as to be able to complete required study activities (i.e. diet record, etc) and able to provide written informed consent.

Exclusion Criteria:

1. Patients with a history of a metabolic disorder including documented defect in urea metabolism (including documented history of gout), carnitine deficiency (primary carnitine deficiency, carnitine palmitoyltransferase I or II deficiency, carnitine translocase deficiency), fatty acid metabolism, beta-oxidation defects, pyruvate carboxylase deficiency, mitochondrial function, porphyria, or nephrolithiasis.
2. Severe acute infection.
3. BMI \> 35.0 or BMI \< 20.0.
4. Active bowel obstruction, ileus, or active or remote pancreatitis.
5. Clinically significant heart failure (NYHA \>2), recent myocardial infarction, or symptomatic atrial fibrillation.
6. Clinically significant renal disease (creatinine \>2.0 mg/dL, urea \>100 mg/dL).
7. Clinically significant hepatic dysfunction (alanine or aspartate aminotransferase \>7 times the upper limit of normal).
8. Patients with insulin-dependent diabetes mellitus.
9. Conditions that may increase the risk of the diet or significantly reduce compliance (i.e. cognitive impairment, frank dementia, etc).
10. Other concurrent experimental therapies.
11. Milk allergy.
12. Treatment with the modified Atkins diet (MAD) for any cause within the 9 months prior to study enrollment
13. Patient inability to complete baseline screening 3-day diet record.