Participants assigned to intensive lifestyle intervention lost a mean ( SE ) 11.1 % ( 0.4 % ) and 7.2 % ( 0.5 % ) of weight at Years 1 and 8 , respectively , compared with 1.0 % ( 0.2 % ) and 3.3 % ( 0.5 % ) in the control group ( p < .001 ) .