Now, the man who was instrumental in helping her shed her weight – trainer Dolvett Quince – is weighing in on the controversy.
"Last night's Biggest Loser Finale has sparked a huge reaction and I do not want the day to end without addressing it," Quince wrote in a Facebook message posted Wednesday night.
"Biggest Loser is a journey which has its ups and downs. Please try not to look at one slice of Rachel's journey and come to broad conclusions. Rachel's health is and always has been my main concern and her journey to good health has not yet ended!"
In a statement, NBC and the show's production company Shine America threw their support behind Frederickson, saying that they "remain committed to helping contestants achieve healthy weight loss and live healthier lifestyles, and to inspiring viewers to do the same."
"I just love myself and I am embracing it," Frederickson told PEOPLE backstage on Tuesday shortly after being named season 15 winner.