Biggest Loser finale preview

UNDATED (WHDH) -- Winning the biggest loser and the quarter of a million dollars that goes with it would certainly change Danni Allen's life.

"I, without a doubt, want to be The Biggest Loser,” said Allen.

But going from 258 pounds to 163 pounds has already changed her life.

"I feel whole again and it took clearing out all the mental stuff that I had going on to get to this place,” said Allen.

The climb was also steep for finalist Jeff Nichols.

Following the death of his father, Jeff’s weight ballooned to 388 pounds.

But enduring 11 weeks on the ranch, helped him drop 123 of those pounds.

"Before coming here, I was very clouded, I was in a bad place, mentally. And I didn't look to my future with any optimism,” said Nichols.

Tonight's third finalist is up in the air, both Jackson Carter and

Joe Ostaszewski have to hope that America’s voted them in.

The Utah college student dropped 98 pounds, from 328 to 230.

"A big part of why I came on the show is because I want to show other people that it's possible,” said Jackson.

The one time pro football player meanwhile, lost 125 pounds from 364 to 239.

"I didn't think I could be that healthy athlete, that healthy person again at age 43. I was able to do that,” said Ostaszewski.

Monday night, a season of victory will turn into one final triumph when someone is crowned "The Biggest Loser".