Nitrogen excretion was lower in the 5En % - protein condition ( 4.7 1.5 g/24 h ; P = 0.001 ) and was higher in the 30En % - protein condition ( 15.3 8.7 g/24 h ; P = 0.001 ) compared with the 15En % - protein condition ( 10.0 5.2 g/24 h ) .