 The purpose of this study is to evaluate changes in urine net acid excretion, blood pressure and body chemistry that occur when the dietary acid load is lowered by using a drugdietary supplement similar to baking soda. This may be important for patients with kidney disease because they may have difficulty removing all of the dietary acid load from the body in the urine. Participants with and without kidney disease will be recruited. Each participant will be fed a controlled diet for one week with sodium bicarbonate and for one week without sodium bicarbonate to evaluate these changes. The investigators will also determine if the effect of dietary acid load reduction is different in patients with kidney disease compared to those without kidney disease. 