Losing 400 Lbs., Gaining it All Back and More

Today, a transformation like you would not believe! At 26 years old, David was 600 pounds. At 31, David started exercising and eating right, and without gastric bypass surgery, David says he went from a dud to a stud losing 400 pounds in two years! However, David has transformed himself again, and now, the 43-year-old weighs 656 pounds. David says something happened to him when he was young, and it could be the reason why he can't keep the weight off. David's younger sister, Jen, and David's father say they're afraid David is going to die soon, and Dr. Phil is his only hope for help.