Will diet pills attack the fat transferred after a BBL?

I was taking before my surgery. I am now 6 weeks post op....and would like to go back to my diet and exercise routine and yes, diet pills where in my diet prior to BBL. my fat transfer was very very minamul. Actually quite sad about it. I gained weight just to have more to transfer and got only 425cc in each cheek. PS is stating not enough fat can be harvest for a successful 2 round which is odd because I am overweight. So will the pills kill the little fat that has been transfered? Thank you all for your time