In 2008, Ali Vincent became the first woman to win "The Biggest Loser." It took a lot of sweat, hard work and tears, but the end result paid off: Ali went from 234 pounds down to 122 pounds.

Smiling and svelte, Ali appeared on "The Oprah Winfrey Show" six months after winning "The Biggest Loser" that year. She was 125 pounds at the time -- just three pounds over her finale weight -- but admitted that she struggled keeping the weight off after the show.