Former The Biggest Loser winner Sam Rouen had some choice words for TBL Families contestants last night.

Seven years ago aged 19, Sam Rouen won season three of The Biggest Loser after losing over 70 kilos. Last night the 27 year old returned to TBL: Families for a firefighting fitness challenge, and to show the current contestants what a difference getting fit and healthy has made in his life.

“I was in your shoes not too long ago, well actually a while ago now, and I was 19, inactive, unhealthy, unhappy and overweight. I know how tough it is and how much of a slog it is each day but at the same time believe me when I can say what it’s worth and the reward when you come out the other side,” he said.

“Becoming a firefighter was always a dream of mine and it’s a dream I’ve been living for the past few years. I’m just here as an example to show you how much your life can change and how good it can be once you come out the other side.”

Dropping from 154.6 kilograms to 82.9 kilograms during the 12-week program in 2008, Rouen has been dedicated to maintaining a healthy lifestyle ever since – but says he still remains self-conscious about his body.

“I still don’t like taking my shirt off – even at the beach.” he told the Saturday Telegraph. (Post continues after gallery.)

Despite this, the Campbelltown firefighter managed to overcome the fear and beat hundreds of others for the chance to pose for the 2016 Firefighters Calendar, something that we bet many other people are also, erm, grateful for.

“I’m still extremely self-conscious … I just tried to keep in mind that it was for a good cause,” he said.

Released in late July, the calendar hoped to raise $600,000 for charities including the Children’s Hospital Foundation’s burns units and returned soldiers charity Mates4Mates.

A far cry from the 19 year old who appeared on The Biggest Loser, Rouen is now "addicted to working out", enjoying running, working out with his brother at the gym, and playing sport.

"It really just seems so long ago, I can’t imagine walking around and living in that body any more," he said.

While he certainly looks the part, Rouen has ruled out any appearances on The Bachelor - for the best reason. The 27 year old is is currently dating flight attendant Daniella Schot and the pair look seriously happy.

"I’ve just started seeing someone recently so I don’t think I’ll be appearing on The Bachelor, as fun as that would be. I have trouble talking to one girl let alone a dozen," he told Confidential.

What do you think of Sam's transformation?