Areas where people have little or no access to grocery stores are cropping up in Canadian cities, a new study suggests.

These "urban food deserts" are created as supermarkets — much like the population — abandon the downtown core for the suburbs, explained University of Western Ontario associate professor Jason Gilliland.

Gilliland and colleague Kristian Larsen studied the distribution of grocery stores in London, Ont., and whether they were accessible. 

Contrary to studies of Edmonton and Montreal, where researchers did not find deserts to be a problem, Gilliland and Larsen found that London lacked access to food shops.   

"Supermarket accessibility is poor throughout the city of London," the study said. "The overall findings indicate that distinct food deserts do exist, particularly in the East London neighbourhoods."

They also noted accessibility problems in the city centre.

In a study published in the International Journal of Health Geographics, the pair found the number of residents who had easy access to a supermarket has dropped from 75 per cent to 20 per cent over 40 years.

They created a database mapping supermarket locations between 1961 and 2005 and the changes in accessibility, considering shops that were a 10- to 15-minute walk, roughly 1,000 metres, or a 10-minute bus ride without transfers accessible.

Urban food deserts pose financial, health problems

Gilliland told CBC News that these deserts can seriously affect the health and finances of residents.

Lacking a grocery store, people end up shopping at convenience stores, he explained, where prices are on average 1.6 times higher.

It's not just hurting their pocket books, he said, as the food purchased at these stores is often less nutritious than what is available at the supermarket, increasing the odds of heart disease, diabetes and cancer.

Gilliland said that lower-income people are the most affected by living in the desert, listing examples such as "single mothers who may not have the time to drive across town. People with mobility restrictions. People for whom it would be very difficult to get on a bus with eight bags of groceries."

In order to remedy these problems, Gilliland said cities must actively encourage supermarkets to move into the area.