hi welcome to health care magic. It is uncommon to have type 2 diabetics at your age of 16 ; but as you seem to be obese, the diagnosis of type 2 diabetes has probably been entertained. Distended abdomen could be fat, gas or free fluid however as you can suck it in, i guess it is normal belly fat. if you still need further confirmation, you may go for ultrasound abdomen. if your diabetes is not well under control that with the world lyrics oral drugs then you might require in film insulin. All the best.