It's believed about 500,000 Kiwis are too poor to afford approproiate food, but the number is based off the City Mission's best guess because there's been no proper measure for more than a decade.
Auckland City Mission general manager for social services Helen Robinson is calling for a measure on food insecurity in New Zealand as a way to properly understand the issue of poverty.
Ms Robinson told TVNZ1's Breakfast she completed a master's degree on food insecurity in New Zealand after working at the mission for years.
She recalled people lining up for food every day, especially at Christmas time when hundreds approach in need of food and presents.
"About four or five years ago there was a morning, one morning that was a very hot morning, and there were literally hundreds of people there," Ms Robinson said. "Something happened to me deep inside and I became so upset and disturbed by the reality that we were seeing."
Ms Robinson said she Googled food insecurity in New Zealand but found a lack of information about how big the issue really was.
"I saw actually that we don't really know enough or a lot," she said. "I saw that the last time we measured food insecurity was over 10 years ago and I determined that we have to do something so I did.
"This is a public health crisis - reality of food insecurity in New Zealand.
"With the best information the mission has, we believe about 10 per cent of New Zealand is food insecure. So [there are] about 500,000 people in our country, like the hundreds that you have seen today, who don't have enough appropriate food. What we're calling for is to measure that."
Food insecurity means people don't have enough appropriate food, meaning having enough food you need on a nutritional or cultural level.
The measurement was used in 2008, and Ms Robinson said we need to use it now.
"To be able to go forward, we need to really come to deeply understand what is the level of food insecurity in our country and how does it affect people."