Chris Willis, 47, weighed 27st 7lbs and needed an inhaler to give him enough breath to walk a few yards.
"But the hardest thing was seeing my little girl in the garden and not being able to join in because I was so unhealthy," said the painter and decorator from Shepreth, Cambridgeshire.
And so, after a lifetime of fry-ups, takeaways and pork pies, Chris cut out all the fatty foods and began exercising.
Chris used to tuck into an incredible 5,000 calories a day, before he switched to a healthy lifestyle.
SWNS Chris at the start of his bid to lose weight
He used to eat five slices of buttered toast for breakfast before a full English breakfast as a mid-morning meal. He would then eat a sandwich, a large pack of crisps and a pasty for lunch before chomping on a whole packet of biscuits in the afternoon. And for dinner he would get through a curry, ice cream, and sink four pints of beer, before snacking throughout the evening.
Now he claims he still eats the same amount - but has simply cut out the unhealthy fatty foods.
He now weighs 16st 7lbs after losing a stone-and-a-half every month since July.
"A few months ago when I started getting active again I remember chasing my daughter around the garden," Chris said.
"When she suddenly turned around with an amazed look on her face and said, 'Daddy, I didn't know you could run'."
Delighted Sophie said: "I'm so proud of my dad. It's brilliant being able to run around and play with him."
"My family and friends have been so supportive and my wife and daughter are so pleased for me," said Chris. "
In fact it's them I did it for more than anyone else.
"The whole journey has been amazing and I am still shocked myself that I have managed to lose so much weight." Chris is now aiming for a new target weight of 15st.