
Researchers found that the increase was highest for girls ages 10 to 14 in the U.S., rising by nearly 13% since 2007. The increase for boys of the same age was 7%.
(Image credit: Nicole Xu for NPR)

Researchers found that the increase was highest for girls ages 10 to 14 in the U.S., rising by nearly 13% since 2007. The increase for boys of the same age was 7%.
(Image credit: Nicole Xu for NPR)