Eighty-three Asian , term neonates ( mean SD birth weight : 3.3 0.4 kg ; gestational age : 39.4 1.3 wk ) were studied at a postnatal age of 13 5 d. Mean requirements for isoleucine , leucine , and valine ( measured in boys only ) were 105 mg kg ( -1 ) d ( -1 ) ( r ( 2 ) = 0.61 , P < 0.001 ) , 140 mg kg ( -1 ) d ( -1 ) ( r ( 2 ) = 0.26 , P < 0.01 ) , and 110 mg kg ( -1 ) d ( -1 ) ( r ( 2 ) = 0.35 , P = 0.001 ) , respectively .