Why do women go through puberty?
All the changes that you experience during puberty are to prepare your body for reproduction, having a baby.

Is it normal to put on weight during puberty?
Yes. During puberty your body starts to lay down fat, around the tum, bum and thigh areas. This is to protect the reproductive organs. Your limbs also grow and you become taller. These are all signs that you are healthy and developing normally.