Mick Keilar joined a fitness program and got to work.

The father-of-two, who once tipped the scales at 140 kilograms, started an eight-week challenge at 117kg.

Mr Keilar, affectionately known as Turtle, took out The Natural Transformer prize at the end of September following a stunning turnaround.

He now weighs 96kg and has "reclaimed my life".

"I just really dug in and focused. I changed my nutrition," he said.

"I was always eating wrong and I gave up the booze, that was a major part of it, and it just gave me something to strive for in COVID.

"You can imagine trying to exercise at 43-years-old and being overweight and obese.

"But it's just amazing now. I have got my life back, probably put 20 or 30 years on my life."

Mr Keilar said he was at a crossroads before the program and knew he had to make sacrifices.

"I could have chosen to do nothing and head back towards 140 kilograms through COVID but I chose to dig in and do the hard yards and reclaim my life back from all the years of food and booze abuse I put it through," he said.

"So in April I started the program and decided to give up alcohol.

"It was a lot easier than I imagined. I had support and encouragement from my family and close friends."

The challenges will keep coming. He's still using the program and plans to shed another 10kg.