The 26-year-old marketing manager from Brisbane, who lost 19.2kg during her time on the weight loss show, said that she was very disappointed when her teammates decided to put her up for elimination against Graham Pilson.
After fellow white team members Michelle Cortesao, Selena Brown and Kasey Cheesman revealed that they wanted her to enter elimination, Gilchrist said to Cortesao and Cheesman: "I wish you guys had been honest with me from the start.
"The three of us had discussed that we would vote for Selena. It's quite obvious that things aren't always as they seem."
After appearing in the elimination room, Gilchrist told voters Lydia Hantke, Lisa Ritherdon, Hamish Elliott and Margie Cummins: "I certainly was a little blindsided by the team. Michelle and Kasey have lied to my face. I feel stabbed in the back, so it's hard to be here."
After it was revealed that she would be leaving the Biggest Loser competition, Cummins told Gilchrist that her vote had been "nothing personal", adding: "[It] is based on who I think needs to stay here. I hope I'm forgiven after this. This wasn't an easy decision and I can't help but feel I've let you down, Bek."
Gilchrist replied: "I'm obviously devastated. I'd give anything to stay here and have another chance. I'll have to do the best I can on the outside. There are no grudges whatsoever. I wish you all the best on your journeys, I really do."
After leaving, she added: "It's been enlightening and it's been enriching and I don't think that my life will ever be the same. I'm so grateful for every person that I've met on this journey. I've learnt that I'm a strong person and that I really love who I am. My future is incredibly bright."
Earlier this week, Luke Stephens was kicked out of the contest for smuggling alcohol into the house and getting drunk.
> Former 'Biggest Loser' star Lara Whalan: 'I feel sorry for Selena'
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