Acetoacetate and Acetate Metabolism in Patients With Chronic Kidney Failure.(RENO-TEP)

Inclusion Criteria: * BMI between 18.5 and 40 * Kidney failure if GFR betweem 30 and 60 mL/min/1.73m2 * Stable medication for at least 4 weeks Exclusion Criteria: 1. Receive cytotoxic therapy for primary or secondary kidney disease within 6 months prior to enrollment 2. Organ Transplant History 3. Class IV congestive heart failure (New York Heart Association) 4. Myocardial infarction, unstable angina, stroke or transient ischemic attack within 12 weeks prior to enrollment 5. Coronary revascularization (percutaneous coronary intervention or arterial bypass) or valve repair/replacement within 12 weeks of enrollment or is scheduled to undergo one of these procedures within 4 weeks of enrollment 6. Any condition outside the realm of renal and cardiovascular disease, such as, but not limited to, malignancy, with a life expectancy of less than 2 years in the clinical judgment of the investigator 7. Active malignancy requiring treatment at Visit 1 (except successfully treated basal or squamous cell carcinoma). 8. Hepatic impairment (aspartate transaminase or alanine transaminase \>3x upper limit of normal; or total bilirubin \>2x upper limit of normal at time of enrollment 9. Pregnancy or lactation 10. Adherence to a ketogenic diet, consumption of ketogenic products or supplements or intermittent fasting or other diet or supplements that may significantly increase ketones in the past two months. 11. Daily alcohol consumption \>2 servings per day 12. Participation in other interventional research projects concurrently or participation in other PET research projects in the last year, which exceeds the recommended limits 13. Inability to lie still in supine position; 14. Medical fluid restriction limiting fluid intake for the procedure