Nephrotic patients show various abnormalities in protein kinetics. Plasma albumin levels and the total plasma albumin pool are reduced. The rate of hepatic absolute and fractional albumin synthesis are increased. Transferrin synthesis is also increased. Fibrinogen levels are elevated in nephrotic syndrome because of an increase in the hepatic synthesis. Regulation of albumin and fibrinogen synthesis seems to be coordinated. A low protein diet has been proposed as a therapeutic tool in nephrotic patients--clinical studies have shown that such a diet reduces proteinuria and increases renal survival. Nephrotic patients can adapt to moderate protein restriction with no sign of malnutrition and maintenance of a neutral nitrogen balance. Albumin and fibrinogen synthesis are ameliorated by dietary protein restriction and these changes are correlated with the beneficial effect of the diet on proteinuria.