Joseph Finau in 2014, left, and nearly 100kg lighter in 2016.

Two years ago, Joseph Finau weighed 220kg - and knew he was facing dialysis if he didn't change his lifestyle.

Today, the south Auckland father is nearly 100kg lighter, and said he owes it all to "nutrition and eating healthy".

Finau, who lives in Mangere, was diagnosed with type two diabetes in 2013.

SUPPLIED Joseph Finau with his late wife Lisa.

His wife, Lisa, died of breast cancer in 2014, leaving him a solo dad to their six children - two of whom have autism.

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Finau said he suffered from depression and was "in a bad state" after Lisa's death.

KYMBERLEE FERNANDES/FAIRFAX NZ Mangere resident Joseph Finau went from 220kg to 126kg.

But he knew he had to make a change for the sake of his health.

"My whole family has type two diabetes. I had to change my lifestyle."

Finau, who now weighs in at 126kg, dropped the weight by following the low-carb, high-fat diet - swapping bread and hot chips for vegetables, coconut cream and corned beef.

KYMBERLEE FERNANDES/FAIRFAX NZ Joseph Finau doesn't go to a gym - instead, he exercises wherever he can.

"Everywhere you look it's just low carbs."

Nowadays, his typical morning starts early.

"At 5:30am I do my mindfulness reading and listen to motivational music. That's my fuel for the morning.

SHILO KINO/FAIRFAX NZ The Finau family pictured in 2014.

"Then, I do my cardio and work out using resistance bands. I also work on my upper body."

Finau also meets regularly with other type two diabetics in south Auckland, giving them tips and a dose of motivation.

"As Pacific Islanders, we are taught that we are diabetics and this is our life," he said.

"Food is medicine. If you need to take your meds three times a day, eat your food three times a day."

Those wanting to change their lifestyle need to put themselves first, rather than their children, spouse or mortgage, he said.

"They're putting all that weight on themselves. What they need to do is take that person from the bottom and put him on top".