Biggest Loser Winner Rachel Frederickson to PEOPLE: I Was 'Too Enthusiastic' with Training

When Rachel Frederickson revealed her new, size 0-2 figure on the Feb. 4 finale of NBC's The Biggest Loser, she thought she would wow friends, family and viewers – and maybe win the title of Biggest Loser. She did win, but the 24-year-old voice actress also ignited a firestorm of controversy about her dramatically

slimmed-down figure, down to 105 lbs. from her starting weight of 260 lbs. (At 5'4", her height-weight ratio puts her BMI at 18, below the threshold doctors consider normal.)

Sitting down with PEOPLE in Los Angeles, just days after she made headlines for her striking transformation, Frederickson says she maintained a 1,600-calorie daily diet, working out six hours a day in the three months before the finale.
The Biggest Loser' Season 15 finale

Rachel Frederickson walked on stage to applause, wearing a wispy silver dress that showed off her new figure. But it soon sunk in that Frederickson had lost a dramatic amount of weight since the last time viewers saw her.