The body fat of boys gradually increased during preadolescence, while gradually decreased during adolescence.
男生体脂在青春期前呈逐年增加趋势，而在青春期后则逐年下降；
"Initiatives such as parental leave for men and parenting classes that emphasize the role of fathers could help to maximize children's development from early childhood to preadolescence," says Serbin.
