Many Auckland families are have under $7 to spend on each meal, Auckland City Mission says.
The Mission is today launching its winter appeal to "raise the breadline" saying thousands in Auckland are struggling to feed their families.
Mission social services general manager Helen Robinson said many families in the city are living on just $720 a week.
Once they have paid rent, debt, power, transport and medical costs, there was very little left to spend on food.
"The heartbreaking reality is that means a family of three has just $6.43 to spend on each meal," Robinson said.
"It also means their access to enough quality, nutritious food is severely restricted."
The New Zealand Health Survey by the Ministry of Health last month found that in 2015 and 2016 nearly one in five children in New Zealand were living in homes with food insecurity.
"The impact of that is obviously poorer nutrition, poorer health and significantly more stress suffered by these families," Robinson said.
The study found that these children had poorer parent-rated health status, proper nutrition, higher rates of overweight and obesity and also more likely to have developmental or behavioural difficulties.
Parents of children in food-insecure household were also negatively impacted, the survey found.
They were more likely to report psychological and parenting stress, as well as have poorer self-rated health status.
AUT University Master of Gastronomy student Nishita Chandra said it would be "a stretch" to feed three or four family members a nutritious meal for under $7.
"It would be a choice of between nutrition or just filling your stomach," Chandra said.
The cheapest options for a fairly nutritious feed she said would be pasta with carrots, onions and frozen vegetables.
"At this budget, meat is generally out of the question. I would have suggested eggs, but that too shot up in price recently," she said.
"Canned food would be another option for getting some relatively cheap alternatives."
Chandra said families on such tight budgets should look out at the bargain section of grocery shops and supermarkets for products or even meat that may be close to expiry.
Last winter, Papakura mother-of-two Louise shared with the Herald that she was forced to feed her family on less than $60 a week despite working as a teacher aide and living in a house shared with extended whanau.
Louise said she earned about $200 less per week than she would if she was on the benefit.
"Like all mums on a tight budget I lose sleep. I lose my appetite. I have to watch out for depression. It can be pretty tough," she said at the time.
Robinson said the Mission's appeal was looking to raise money to continue to run its services and support it provides to Auckland's most vulnerable people.
"We also want to raise awareness of food insecurity and just how devastating, wide-reaching and long-term the effects can be," she added.
Donations are tax-deductible, and can be made online through its website, over the phone by calling 09 303 9209, or at the Mission's 23 Union Street reception.
Food contributions can also be dropped off at the Mission.