A new study by the Greater Chicago Food Depository says one in five Chicagoans are “food insecure.”

The agency looked at data from 77 city neighborhoods and 119 Cook County suburbs over the past decade. It says that 20.6 percent of Chicagoans and 15.4 percent of Cook County residents report a decrease in quality or quantity in their diet.

“Hunger [in the past] has been defined by did you go to sleep wishing you had something else to eat or not having enough food,” says Mari Gallagher, principal of Mari Gallagher Research and author of “Examining the Impact of Food Deserts on Public Health in Chicago.”

She said she does not find the statistics surprising.

“Hunger today also has a lot to do with people running down to the fast food place and, for a couple of dollars, filling up on a lot of empty calories,” Gallagher says.

The Depository survey found the most insecure communities were concentrated on the Southwest and West sides of the city. In Chicago proper, Riverdale (40.8 percent), Washington Park (34.0 percent), Englewood and North Lawndale (both 31.2 percent) had the highest rates of food insecurity, while Ford Heights (55.5 percent), Robbins (45.0 percent) and Dixmoor (38.7 percent) had the highest rates in the suburbs.

For comparison, the national and state rate for food insecurity last year was a little more than 14.5 percent, according to a 2010 survey by the USDA.