Those students in the intervention group reduced their BMI z-score ( -0.21 , 95 % CI -0.34 to -0.07 , P = 0.003 ) and body fat ( -2.67 % , 95 % CI -5.12 to -0.22 , P = 0.033 ) compared to wait list control group with statistical significant , and the intervention group also had a significant reduction in BMI z-score ( -0.06 , 95 % CI -0.11 , -0.007 , P = 0.028 ) and body fat ( -1.71 % , 95 % CI , -3.44 to 0.02 , P = 0.052 ) after a 4 month maintenance period .