[wizzness]

I'm 19 years old and over the last couple of years I've started to gain weight where I've never had it before. It used to go straight to my butt but lately subcutaneous belly fat (starting directly beneath the belly button) has become a problem. Could anyone give some insight as to what could be responsible for this kind of fat? oestrogen? cortisol? insulin?
Thankyou for any help you can give, I've become somewhat obsessed with this