The renal haemodynamic response to a meat meal is usually measured as either filtration capacity (maximal achieved GFR), or renal reserve (maximal GFR increase over baseline), or percent renal reserve (maximal GFR increase as a percentage of baseline). The time-course of GFR response to a meat meal varies in different individuals as the peak GFR tends to occur late in renal disease. This study proposes a new method to measure the GFR response independently of differences in peaking time.