Fig. 1. A. Correlation between 24-hour urinary nitrogen to potassium ratio and 24-hour urinary net acid excretion (mmol/d) on day 14 (baseline) in 40 subjects (r = 0.528, P < 0.001). B. Correlation between change in the 24-hour urinary nitrogen to potassium ratio and change in 24-hour urinary net acid excretion (mmol/d) from day 14 to 74 in 40 subjects (r = 0.453, P = 0.003). Triangles represent subjects given meat and cereal food substitutes and circles represent subjects given meat and fruits and vegetables.