Sam Rouen entered the Biggest Loser Australia reality TV show 10 years ago as an obese teenager desperate to lose weight.
A decade on, Rouen has not only lost the weight - a whopping 79kg - but has turned into a calendar-worthy firefighter.
Rouen won the third season of the TV show in 2008, aged 19, and has defied all scientific odds by keeping the weight off and improving his physical condition even after the show ended.
He took to his Facebook page to celebrate how far he's come, one decade on.
"Wasn't sure if I was going to do this post … however. 10 years hey. What a time. So much has happened, good, bad, everything between," Sam said in his post, accompanying a before and after photo of his health journey.
"Highest highs and lowest lows. All I know is I've got some amazing people in my corner and I'm unconditionally appreciative of that."
Rouen posed shirtless for a sexy fireman's calendar to benefit a local children's hospital in 2016, but says he remains extremely shy and self-conscious. "I just tried to keep in mind that it was for a good cause," he said about the photo.