Im 13 im 5'1 and weigh around 52kgs. I know im in the healthy weight range but im starting to get a belly and stretchmarks on my thighs beause i am going throuh P<U>B<U>R<T>Y<><>. I got some bio oil for my stretch marks lastnight. And for eating ive been eating more salads and fruits and veges. every night i do 10 sit ups (i have been doing that 4 a couple months) and i started doing 10 when i wake up aswell this morning. what do you think? thanks