In less than a decade, healthcare for diabetics will cost the country more than $1 billion a year unless New Zealanders start watching their diets, Diabetes New Zealand says.
On average, 50 people were diagnosed with diabetes each day last year, increasing the total number with the incurable type-1 by just under 10%.
Diabetes New Zealand national president Chris Baty said the increase was mainly fuelled by a hike in type-2 diabetes, linked to obesity.
Nationally, 208,076 people had diabetes at the end of last year, latest Health Ministry figures show. The ministry expected a further 21,000 diagnoses by the end of this year.
If the "alarming" rates continue, 400,000 New Zealanders would have diabetes in less than a decade, which would cost more than $1 billion in annual healthcare costs, Baty said.
"If we do nothing to stop the growth in obesity, the cost to our country will be crippling, and not just to our health system. The reality is there is no quick fix."
Baty said obesity was one of the largest preventable causes of type-2 diabetes.
"While there's no silver bullet, we do know we can prevent obesity through lifestyle interventions that focus on diet and exercise."
Both types of diabetes can cause serious health problems if not managed properly, including eye and kidney damage, foot problems, limb amputation and premature heart attacks.
The number of people with diabetes in the Capital and Coast District Health Board catchment rose by 8.4% to 10,461 last year.
Wellington diabetes specialist Jeremy Krebs said while there were initiatives to help people manage their diabetes, there was a lack of focus and funding on prevention.
The emergence of a diabetes epidemic had been discussed for 10 years, but no action had been taken.
"I think it's time for the Government to stand up and make some hard decisions when it comes to things like fat tax, GST on fruit and vegetables, really dealing with the food industry head on, and transport issues and policies in schools for healthy kids."
If nothing was done, there wasn't a "hope in hell" of reversing the looming epidemic, Krebs said.
Porirua Union Health Service GP Bryan Betty said the figures were just the tip of the iceberg.
Between $5000 and $13,000 was spent every year on care for each diabetic patient, and for every diabetic probably two people had pre-diabetes.
Betty, who is on the national diabetes guidelines group, said even teenagers were being diagnosed with what used to be considered an elderly disease.
Cutting schemes such as Health Eating Healthy Action (Heha) - an integrated nutrition, physical activity and obesity strategy established in 2004 - was a backward step.
Some Heha funding will be reallocated to a new programme, Health Ministry group manager national services purchasing Warren Lindberg said, "particularly around maternal and newborn nutrition where evidence shows good maternal and infant nutrition help prevent obesity later in life".
About $50 million a year is spent on keeping children and people active, including KiwiSport, Green Prescriptions and the Fruit in Schools programme for low decile schools, he said.