Mayors across the country say that residents' requests for emergency food aid are on the rise, but a lack of resources has caused cities to turn down many of them.

The findings were revealed in a study published by a group of 25 mayors belonging to a U.S. Conference of Mayors task force on hunger and homelessness.

Collectively, the surveyed cities saw their emergency food budgets increase by 11 percent to $251 million this year. While cities distributed essentially the same quantity of food in 2011 as they did in 2011, in almost all the cities surveyed, emergency kitchens and food pantries reduced the amount of food offered to each resident due to rising demand.

Even with the reduced portions, some cities reported that significant numbers of people who needed emergency food assistance didn’t get it. In places like Nashville, Philadelphia and San Francisco, nearly a third of the demand for food aid has gone unmet, and in San Antonio, 40 percent of the demand went unmet.

The study also revealed that the overwhelming majority of the cities surveyed had shelters that turned away both families and individuals due to a shortages of beds.

“We’re not proud of the results,” Philadelphia Mayor Michael Nutter said a conference call with reporters Thursday.

The study isn’t representative of all cities, since the task force members are a self-selected group. But it does underscore the challenges facing local governments at a time when many American cities are still reeling from the demand for increased social services coupled with decreased revenue.

The figures come at a time when real median household, which factors into inflation, dropped 1.5 percent last year to $50,054 according to the Census.That’s 8.1 percent below 2007, the year before the recession.

Especially troubling is the overall tone of pessimism among the mayors surveyed. Three out of the four cities included in the survey reported that they expect requests for emergency food aid to increase over the next year, and almost half say they expect the resources to provide that assistance will decline.

The mayors took the opportunity to make the case for federal programs designed to address homelessness, poverty, and hunger. While the federal food stamps program, known as SNAP, is exempt from the automatic spending cuts that would occur if Congress fails to avert the so-called fiscal cliff, affordable housing programs and Community Development Block Grants – which fund a variety of programs at the local level geared towards low- and middle-income residents, are not.

Nutter also expressed concern that the federal school lunch program could be affected by an alternate plan floated by the House Speaker John Boehner (R-Ohio) as a solution for the so-called fiscal cliff.  That proposal would cut spending in programs such as Medicaid, food stamps and the health care reform law.

The following cities participated in the study: Asheville, N.C.; Boston; Charleston, S.C.; Charlotte; Chicago; Cleveland; Dallas; Denver; Des Moines; Gastonia, N.C.; Los Angeles; Louisville; Minneapolis; Nashville; Norfolk, Va.; Philadelphia; Phoenix; Portland; Providence, R.I.; San Antonio; Saint Paul, Minn.; Salt Lake City; San Francisco; Trenton, N.J. and Washington, D.C.