HOBART real estate agent Erin Hibberd said losing 72kg, or about half his body weight, had been as easy as falling in love - with Tassie's wilderness.
Mr Hibberd, 41, said his life was transformed at age 36, when he fell head-over-heals in love with Tasmania's wilderness.
And he said Hobart's inspiring 200kg-plus Glenn Nelson had set the right example by taking advantage of the state's great outdoor experiences such as climbing and swimming.
A former workmate, Michael Bostock, had been nagging Mr Hibberd - his 152kg boss who hated exercise - that he needed to go on a long bushwalk.
Eventually Mr Bostock and another workmate dragged their boss into the Walls of Jerusalem National Park for a three-day walk and mountain climb.
Mr Hibberd said his conversion was instant. Within weeks, he had completed the Cradle Mountain-Lake St Clair overland track, solo.
It was the start of an incessant love affair that, over four years, transformed him into a lean machine, whose latest crush is rock climbing.
"It was like escaping from prison," he said. "It changed my life."
Mr Hibberd said that in his early 30s, he had tried everything from dieting to gym memberships. He said they hadn't worked and once he had found his passion he didn't need them.
"You've just got to put the boots on," he said. "I didn't change anything else. If your life is filled up with positive things, the detrimental things are squeezed out."
Mr Hibberd said the completion of a 10-day traverse of one of Tasmania's toughest non-tracked wilderness areas, the Eldon Ranges in the Franklin-Gordon wild rivers National Park, with friends earlier this year, had been a massive thrill.
A climb planned this week on Mt Wellington's Organ Pipes promises to be another.