ET has a sneak peek at tonight’s finale of MTV's "I Used To Be Fat: Past to Present." Nine high school students are competing against themselves to slim down over the summer before their first day of college. Did everybody make it?"In the beginning I was really gung ho, I was super excited, you know, ready to change my life and then I lost 36 lbs. and I kind of lost my groove and got out of the motivation of everything," contestant Tanner says to MTV's SuChin Pak.Thanks to the help of personal trainers along with family influences, these nine teens learn that finding out who they are during the process is as gratifying as the initial goal of losing weight. One participant in particular, Makenzie, acquires support from her father in uncovering her true identity. "I've always known she was a beautiful girl," says Jim, Makenzie's dad. "She's my daughter and I'll always love her but she didn't realize that and so it's been a struggle for her and I'm really proud of her." (ETonline.com)