Those students in the intervention group reduced their BMI z-score ( -@ , @ % CI -@ to -@ , P = @ ) and body fat ( -@ % , @ % CI -@ to -@ , P = @ ) compared to wait list control group with statistical significant , and the intervention group also had a significant reduction in BMI z-score ( -@ , @ % CI -@ , -@ , P = @ ) and body fat ( -@ % , @ % CI , -@ to @ , P = @ ) after a @ month maintenance period .