The migration of supermarkets to the suburbs has left some Canadian cities with "food deserts" in their most vulnerable neighbourhoods, according to new research that counters previous studies suggesting that phenomenon wasn't happening in this country.
Residents marooned in these grocery wastelands -- usually those who can least afford it -- have no easy access to stores that stock fresh, affordable food, researchers say, forcing them to pay convenience store prices or eat junk food.
It wasn't always that way.
"We found the location of all grocery stores in 1961 and discovered that the central neighbourhoods and poorer neighbourhoods had incredibly good access to supermarkets," says Jason Gilliland, a geography professor at the University of Western Ontario who used London as his living lab.
"Over the last 40 years or so, grocers have really left the core for the suburbs. It's another side-effect of suburbanization."
Gilliland and his co-author, Kristian Larsen, used computerized mapping to plot the location of London's supermarkets in 1961 and 2005. Then, using census data, city maps and bus schedules, they calculated each neighbourhood's access to grocery stores using real-life criteria such as a 1,000-metre walk (10 to 15 minutes) or a 10-minute bus ride with a short walk on each end.
Not only is access in many areas worse now, they found, but the poorest neighbourhoods are the most stranded.
"If you think about a single mother with limited income without a vehicle -- if you can't hop in your car and drive to a supermarket, you must shop locally," Gilliland says.
"You're going to be buying groceries at local convenience stores."
That forces people to pay an average of 1.6 times more for groceries, he says, perpetuating a financial "downward spiral" for those already in a precarious position.