Ben Muscroft once weighed in at 27st and eight pounds (175kg) after enjoying a diet of a bacon, sausage and egg sandwich for breakfast, fish and chips for lunch, and spaghetti bolognese or pizza for dinner, along with cans of cider or two bottles of wine.
But after making a commitment to switch to fruits and fat-free natural yogurt to start the day and a homemade coriander and mint chicken dish to end it, has seen him successfully shift 15st and eight pounds (99kg) to drop from a t-shirt size XXXXXL to having a more slender 34ins waist.
The care worker, from Sheffield, struggled with his weight since childhood and reached a point where he was unable to roll over in bed because of his size.
The full extent of his health problems became apparent during a trip to see his brother in China in 2012, during which Mr Muscroft faced the embarrassment of having to ask for a seatbelt extension on the plane.
During the holiday, he was unable to take part in activities like walking on the Great Wall of China, and locals stared at him because of his size.
Mr Muscroft said: "Just getting to China was a bit of a battle. I had to ask for a seatbelt extension in front of the entire plane which wasn't the greatest of starts.
"Then the tray table wouldn't lie flat so I had to eat my meals at a strange angle. It wasn't a pleasant way to spend 20 hours.
"Then when we got to China, my size meant I missed out of certain activities. We visited the Great Wall of China, but I was too unfit to walk any of it, which I really regret."
The slimmer added: "I also became something of a talking point because many people had never seen anyone my size before - so the looks and stares were plentiful.
"When you weigh more than 27st even the simplest tasks really take it out of you. I couldn't walk the short distance to Hillsborough football stadium without getting out of breath."
After his trip, Mr Muscroft realised that "something had to change", and, following the example of his father and sister, reluctantly started attending a Slimming World group in Hillsborough in March 2015.
Although previous attempts at weight loss had failed, his better eating habits were coupled with a commitment to exercising regularly and, after discovering a passion for boxing and yoga, he successfully ran his first half-marathon in a time of one hour and 50 minutes.
After being crowned Slimming World's Man of the Year 2019, Mr Muscroft hopes to enjoy a more active trip to China next year with his new girlfriend, Karen.
Describing his weight-loss journey as the best decision he has ever made, Mr Muscroft said: "It's not just the health benefits - it's freeing yourself from all of the things that used to hold you back."