Losing weight was just the beginning of the success story for Ahipara couple Trevor and Danielle Beatson.
Now they have created an app for weight loss coaches, and have been chosen for a mentoring programme backed by Massey University.
The next step could be exhibiting at a Silicon Valley conference in October, taking the app to the world.
Trevor said the "accidental entrepreneurs" were very humble and grateful for the support they received.
It all started in mid-2017 when the former policeman decided he needed to lose some of his 170kg.
"I had really poor health - blood pressure, pre-diabetes, sleep apnoea, aches and pains, everything hurt. Every obesity-related problem, I had or was on the way to," he said.
He began a low-calorie diet, supported by vitamins and supplements. He lost 20kg in the first month, inspiring his wife to join in. The former teacher lost 12kg, and decided to start coaching friends and family who were interested in the diet.
The weight-loss success meant client numbers kept growing, but trying to manage up to 50 clients using email, Facebook messenger and phone calls all began to become too difficult.
"It became very difficult to manage that many people, track their progress and manage their health journey," Danielle said.
The couple discovered that there weren't any apps on the market specifically for weight-loss coaches, so they decided to create their own.
"We rolled out the butcher's paper that teachers use on the deck and started drawing what we wanted on each screen," Trevor said.
The app, iLose, was unique amongst the thousands of weight-loss apps because dieters
connected to a real person.
"It's all about connection, accountability and feedback between weight loss coaches and their clients."
Since launching in September last year, the app had been used by 200 coaches and 3300 clients, but the couple knew they needed guidance as novice entrepreneurs. So they applied to the Global Sprint programme run by Massey University business incubator, ecentre.
iLose was one of just seven start-ups selected for the programme from 50 applications.
The ecentre programme involved an initial meeting in Auckland with the other start-ups and 20 mentors. Since then there have been weekly meetings in a virtual classroom, plus one-on-one mentorship.
iLose is mentored by Ralf Wittgen, from CS Inspire, and Ross Tweedie, from Pita Pitt.
Trevor said the learning curve was "10-fold," with a focus on growing customer numbers and perfecting the business pitch. The programme continues for four weeks.
The couple also hope to be involved in Stage II of the Global Sprint programme, starting in May. And they would like to take part in a week-long learning experience in Silicon Valley, including exhibiting in the New Zealand start-up pavilion, hosted by ecentre, at the TechCrunch Disrupt conference in October.