Winnipeg's poorest families face a long and expensive journey to get groceries because they live in a virtual food desert.

Using a combination of data from Manitoba Health's food handler registry and store listings from company websites, the CBC I-Team has identified and mapped 74 grocers that met criteria generally used by groups that study food access and community health.

The analysis reveals a vast area at the core of the city — spanning over 30 square kilometres — in which no major grocers operate.

Groups that study food security generally consider one kilometre as being on the outer limits of what is considered accessible for all residents. The map below illustrates a one-kilometre radius around each grocery store used in the analysis. Areas that fall outside these buffers zones are considered less accessible.

How we chose which food seller to include in our analysis:

In collaboration with experts that study food access and community health, the CBC I-Team focused only on grocers that met the following criteria:

A customer could conceivably and consistently purchase the items found in Health Canada's National nutritious food basket.

Is a medium- to full-sized grocer (minimum of approximately 10,000 square feet).

The store operates as part of a stable grocery chain.

According to the city's neighbourhood census data, nearly 70,000 people call the food desert home.

Katherine Thomas, who lives on Burrows Avenue, is among them. Thomas has seven mouths to feed on a fixed income and often has to choose between paying bills or putting food on the table.

Katherine Thomas bundles her children up and takes two transit buses to the grocery store outside the food desert in Winnipeg's core area where she lives. (Jeff Stapleton/CBC) "It's always juggling the food and the bills," she said. "Sometimes I think, 'Food or utilities?'"

Thomas relies heavily on school lunch programs for her children and often dips into community supports such as the food bank.

"It's really hard," Thomas said. "You feel lost when you don't have enough food."

Once a month, Thomas goes grocery shopping. She has to enlist the help of one of her older children because she buys in bulk to make the money go further.

Katherine Thomas lives in Winnipeg's core food desert. (Jeff Stapleton/CBC) First, she has to bundle up her younger children and catch two buses to complete the seven-kilometre trip. Because Thomas is buying in bulk for a monthly shop, she must hire two taxicabs for a total of nearly $50 to ship everything back home, which takes a big bite out of her food budget.

"Usually we wait from half an hour to over an hour. We just stand out there or stay inside if it's really cold," Thomas said. "It's really hard to get cabs, especially on cheque days because everybody is calling cabs."

Thomas said she used to grocery shop at a Giant Tiger store within relative walking distance from her home, although she had to be creative when carrying groceries back home using wagons in the summer and sleighs in the winter.

However, Thomas found there was little in the way of fresh produce and an abundance of processed and frozen foods which didn't last as long in her home.

Sometimes I think, 'Food or utilities?' - Katherine Thomas

"There's too much junk food, " she said of Giant Tiger's selection.

""If we get too much fast foods, then our foods go fast."

None of this surprises Stefan Epp-Koop, the acting executive director of Food Matters Manitoba.

"People with limited food budgets are having to make difficult choices on how they get home," Epp-Koop said, adding that in the food desert, transportation costs often cut deep into already limited family food budgets.

Stefan Epp-Koop with Food Matters Manitoba takes a walk with CBC's Katie Nicholson through the epicentre of the inner city food desert and explains how the consequences of an urban food desert affect us all. 2:12

"I think that what worries me is that people are going to be forced to make bad food choices, and not because they want to but because they have to," Epp-Koop said. "It's all that's available to them."

There are also larger costs to society.

"If people aren't able to access healthy food, they won't be as healthy and we'll end up paying for that as a city and a province," Epp-Koop said.

Stefan Epp-Koop with Food Matters Manitoba says corner stores can be a part of the food desert solution. Homes located at the centre of Winnipeg's food desert — in the easternmost part of Point Douglas — are within three to six kilometres' walking distance from the nearest major grocer. Neighbourhood data from the last census also shows that residents in this area are less likely to travel by vehicle.

"The corner stores are really expensive. Even to get a roll of toilet paper is a dollar," said Thomas.

Although data from the provincial food-handler licensing database shows there are a handful of corner stores and small, independently-owned grocery stores in the area, which help supplement people's dietary needs, prices are generally steeper and the selection is poor.

Comparing the prices of a sample shop consisting of 10 items found on Health Canada's National Nutritious Food Basket, the CBC I-Team found that the final bill at a corner store in the Chalmers neighbourhood was more than 36 per cent higher than at a full-service supermarket in the same region.

The CBC I-Team bought 10 items at a Winnipeg supermarket and 10 items at a corner store in the city's food desert. Here's how the prices compare. 0:35

"It's common to kind of rag on corner stores, but you won't find me doing that," said Donald Benham, hunger and poverty awareness manager with Winnipeg Harvest.

"There are an awful lot of small business owners who are trying to serve people who are underserved, and they have varying degrees of selection that are available. Some of them do try and have fresh meat, some of them have frozen meat. Some of them have some types of produce and so on," he explained.

Donald Benhams of Winnipeg Harvest believes that better transit options could help those living in the food desert. (Jeff Stapleton/CBC)

Still, Benham agrees that access to a full-service grocery store is key for the city's poorest people living in the food desert.

"It's a long way to carry groceries if you don't have access to a vehicle," he said. "In the long term, what we really need is a way of getting people to the grocery stores in a way that doesn't cost them any extra money."

Benham believes the city's bus service could be part of the solution: "One of the things we're asking people to look at is maybe we should change the way we approach public transit."

At Food Matters Manitoba, Stefan Epp-Koop agrees.

"I do think that government, particularly the city government, has some role to play in making sure that Manitobans, that Winnipeggers have access to good food," he said.

The city's core isn't the only food desert in Winnipeg. On Thursday, the I-Team sheds light on the challenges that residents in suburban food deserts face.