There was a significant group time interaction ( P < 0.01 ) in postintervention body weight , with both the POWERS and POWERS ( plus ) groups demonstrating greater reduction in body weight compared with the control group ( POWERS : -2.1 5.5 kg , -2.4 -5.9 % ; POWERS ( plus ) : -0.5 5.0 kg , -0.6 4.3 % ; control : +2.6 5.3 kg , 3.1 7.4 % ) .