Six years ago, Stephen Houghton weighed 151kg, had a high-pressure job, heart and cholesterol problems, sleep apnoea and was pre-diabetic.
Now, the 47-year-old Taranaki father-of-two has shed 67kg and is about to compete in his second Triathlon World Championships.
"I started making some really strange choices in my personal life, as I was convinced I wasn't going to be around much longer and I did not want to leave my family with financial burdens," he said.
"One day it all dawned on me that these morbid thoughts were all wrong. I had everything I ever wanted - a great job at a very supportive company, a wonderful caring wife and awesome kids, so I realised I needed to make some drastic changes if I was to be around for them."
Mr Houghton lost 26kg through changing his diet and walking, and then had a gastric bypass.
Eighteen months after the operation his stomach size was back to normal and he had to work hard to keep the weight off.
He learned about nutrition, joined a gym and ran a couple of half marathons. Then he decided to take things up a notch.
"I just love watching triathlon and the sort of person I am I thought that's a hell of a challenge to do three complete different disciplines and do them well.
"So I literally just hopped in a pool one day and thought right let's do this and I started to swim."
He did a couple of triathlons, got a trainer and went on to represent New Zealand at the age group World Triathlon Championships in Chicago last year.
He quit his job and says he's now addicted to triathlons.
His next big race is Tri Kinloch in Taupo next Sunday. He has already qualified for the standard distance at the World Championships but wants to make the sprint distance as well.
Either way, he will be competing at his second Triathlon World Championships in Cozumel, Mexico later this year.