Thomas McIntyre, 43, from Larne, Northern Ireland, cut a huge figure at six foot tall, weighing more than 31 stone and had a waist measuring 74 inches.
The Celtic fan's goal of shedding the pounds was recognised today at the Ritz Hotel in London where he was named Slimming World Man of the Year 2013.
Mr McIntyre, a fresh food manager at Dunnes Stores, has lost 17 stone 8lb, going from 31 stone to 13 stone 6lb and a size 8XL to a medium.
As well as his dramatic weight loss, the size of his waist has dropped by 40 inches to 34 inches.
Although he laughed off the embarrassing situations he found himself in, his weight was a constant worry to him and he was convinced he would die young.
"I was the typical jolly fat bloke, always making fun of myself before anyone else had the chance to do it.
"Deep down, though, I'd reached the point where I thought about my mortality all the time and the more I worried, the more I ate, to comfort myself I suppose. It was a vicious cycle," he said.
Mr McIntyre had been overweight for more than two decades, since giving up playing football in his early twenties without quitting the junk food his active lifestyle had allowed him to indulge in.
He grew in size steadily and in the run-up to his wedding five years ago he became so worried about his increasing weight that he secretly purchased a bigger back-up suit - it was an 8XL.
"My weight felt like a huge burden when I married my beautiful wife Claire. She's always loved me for me but getting a suit was difficult and I felt awful in it.
"Getting stuck in a turnstile when I went to Partick Thistle's ground wasn't much fun either. After that I had to go in through the disabled gate every time I went to a football game," he said.
Mr McIntyre's weight also left him on medication for a range of health concerns including high blood pressure, breathing problems and fluid retention.
He tried losing weight before and managed to shed 11 stone but his diet left him hungry and he was unable to keep it up.
He regained the weight plus another three stone, making him the biggest he had ever been.
Then in February last year a friend confided in him about how worried she was about his weight and asked him to come to the local Slimming World group with her.
"I was extremely apprehensive. I was worried it would just be another failed diet attempt, but that changed when I met my consultant Jayson.
"He'd lost 9st himself - although he looked like he'd never had a weight problem in his life - and after hearing his story and how passionate he was about helping other people to lose weight, it made me feel like I could do it too.
"And when I came back after the first week and found out I'd lost 10.5lb, I was completely won over."
As the weight started to come off, Mr McIntyre felt confident enough to begin exercising.
He challenged himself to do a little more each day, spurred on by his consultant and his fellow Slimming World members, and now runs three times a week as well as taking his dog on long walks.
But the biggest change is in how he feels about himself. His confidence levels are high, he is learning to drive for the first time and is hoping to start a family.
He said: "Before I joined Slimming World I had no energy, my days off would consist of me just lying on the sofa.
"Now everything's easier and I'm so much happier. If we are lucky enough to have children, I'll be the active dad I always wanted to be and that's really important to me.
"I feel like life passed me by for years so I'm determined to live it to the full now.
"When I first joined Slimming World my friend Mauveen gave me a plaque that said 'Always look on the bright side...'. It's definitely easier to do that now so I'm not pretending to be the jolly fat bloke any more, I'm genuinely happy.
"I can fit through the turnstiles when I go to the football now so there's no embarrassment there. In fact, that's the only downside to my weight loss because I have to queue with everyone else."