The balance between the amount of protein in the diet (anabolic component) and the net acid load of the diet (catabolic component) in part determines whether the diet as a whole has a net anabolic or catabolic effect on bone and muscle. This study will investigate whether the addition of an alkaline salt of potassium, potassium bicarbonate, will allow dietary protein to have a more favorable net impact on intermediary indices of bone and muscle conservation than is observed with protein in the usual acidic environment.