I Used to Be Fat: College is all about reinvention. Its a time in a teens life where they can leave behind all of the preconceived notions people had about them in high school and start fresh. Unless theyre massively overweight. I Used To Be Fat is a new documentary series profiling teenagers desperate to shed their unwanted pounds before heading off to school. Well send a weight loss guru to work with each person and theyll go through rigorous fitness regimens and work with experts to learn how to change the habits that caused them to gain so much weight.