Inpatient visits: Prior to each inpatient visit, participants will be mailed 9 bouillon packets (containing 50 mmol of sodium each) and instructed to consume 3 packets each day for three days prior to admission to the Clinical Trials Center; the purpose of this is to achieve high sodium balance, which is necessary for our measurements of the renin-angiotensin system. The high sodium diet will be continued during the inpatient setting. Female subjects will have a urine pregnancy test done at admission. The following measurements will be performed during the two inpatient visits, and the changes in these measurements (comparing the baseline value with the 8-week value) are the endpoints for this study: