CHICAGO - Hunger is spreading while the number of homeless families is increasing as a result of the recession and other factors, according to a report on Tuesday.

The U.S. Conference of Mayors said cities reported a 26 percent jump in demand for hunger assistance over the past year, the largest average increase since 1991.

Middle-class families as well as the uninsured, elderly, working poor and homeless increasingly looked for help with hunger, which was mainly fueled by unemployment, high housing costs and low wages.

The 2009 report is based on a survey of 27 cities, including Boston, Chicago, Detroit, Los Angeles, Miami, Philadelphia and San Francisco, that comprise the group's task force on hunger and homelessness.

Looking ahead to 2010, cities said they expect it will be difficult to meet increased demands for food due to the impact of state and local budget cuts, a decrease in grocery store donations and higher food costs.

Just over three-fourths of the cities reported a jump in homeless families due to the recession and lack of affordable housing. Individual homelessness, on the other hand, was level or down in 16 of the cities.

This is an indication of the success of policies aimed at ending chronic homelessness among single adults with disabilities, the report said.

Only 10 cities reported having so-called tent cities or other concentrations of the homeless.

Most of the cities in the survey received additional funding to combat hunger and homelessness from the American Recovery and Reinvestment Act.

Cities are using (housing funds) to develop central intake systems for homeless services, coordinate services more closely with surrounding areas, or offer homeless prevention assistance for the first time, the report said.

(Reporting by Karen Pierog; Editing by James Dalgleish)