Pacific people in New Zealand often suffer from high blood pressure and are over-represented in statistics for diabetes, strokes and heart disease.
The boxer, David Letele - known as the Brown Buttabean - used to weigh over 200 kilograms and says he was so fat he couldn't tie his own shoelaces.
This, he said, made him realise the path he was on would lead to an early death.
Mr Letele shed more than a hundred kilogrammes after radically changing his eating habits and doing more regular exercise.
