After 1 year on maintenance therapy , the D group sustained a lower weight ( 11.0 kg , 95 % confidence interval [ 95 % CI ] 9.0 , 12.8 kg ) than those in the E ( 6.2 , 95 % CI 4.4 , 8.1 kg ) and C ( 8.2 , 95 % CI 6.4 , 10.1 kg ) groups ( P = 0.002 by analysis of covariance [ ANCOVA ] ) .