Thirty healthy volunteers ( mean [ SD ] age , 28.0 [ 4.95 ] years ; weight , 59.3 [ 6.51 ] kg ; height , 165.0 [ 7.25 ] cm ; body mass index , 21.7 [ 1.94 ] kg/m ( 2 ) ) were randomly divided into 3 groups , each consisting of 5 men and 5 women .