The intervention group decreased their BMI ( the intervention effect is the difference in change between the groups adjusted for the respective baseline values ( DELTA ) = -2.0 kg/m2 , 95 % CI : -2.5 ; -1.5 , P < 0.001 ) , total body mass ( DELTA = -4.0 kg , 95 % CI : -4.9 ; -3.0 , P < 0.001 ) , and fat mass ( DELTA = -3.3 kg , 95 % CI : -4.2 ; -2.7 , P < 0.001 ) compared to the control group after the intervention .