Miami-Dade County and its largest cities — including Hialeah, Miami Beach, Miami and North Miami — are among the nation’s top losers in federal funding for social services, meaning meals for the elderly and afterschool programs for kids face dramatic cutbacks that will hurt thousands of residents.

Hialeah leads the nation: It will receive $1.8 million less in fiscal year 2012 than it did in 2011 from the Community Development Block Grant fund program, known as CDBG, a major source of direct federal dollars. About half of its CDBG money will be lost.

“Children and seniors will be affected,’’ predicted Mayor Carlos Hernandez, who said his city has no way to fill the gap.

North Miami Mayor Andre Pierre, whose city lost 33 percent of its funding, hasn’t come up with a plan to alleviate the pain. “It affects the most vulnerable of our society,” he said.

Miami-Dade County and the four cities comprise one-sixth of the 30 cities and counties suffering the greatest cuts nationwide, according to numbers recently released by the U.S. Department of Housing and Urban Development, which distributes CDBG funds.

Part of the reason: A funding formula that puts great emphasis on the number of housing units available for an area’s population. That hurt here, because 2010 Census figures suggested that enough new residences were built during the real estate boom to significantly decrease the number of “overcrowded’’ housing units.

But the methodology is flawed, South Florida leaders say, because poor people could not afford to move into the ritzy condos and homes that were built in Miami, Miami Beach, Hialeah, North Miami and unincorporated Miami-Dade over the past decade.

“We are being punished because of the housing boom,” said Miami Mayor Tomás Regalado. “But the new homes were not for poor people.’’

The 2010 Census reported 20,866 people in the four cities and unincorporated Miami-Dade lived in overcrowded residences. The 2000 Census reported 248,578 — more than 10 times larger.

The funding cuts stemmed in part from the budget standoff in Washington D.C. last year, when more than $1 billion was slashed from CDBG funding. Nationally, Sunbelt states like California and Florida are seeing the most severe reductions.

The breakdown: Hialeah was slashed to $2 million, a drop of 47 percent. Miami Beach lost 42 percent of its funding, down to $910,000. Miami-Dade government plummeted 35 percent to $10.6 million. Miami dropped 34 percent to $4.9 million. And North Miami was cut 33 percent to $744,000.

Broward County government lost 31 percent, and Coral Springs, Hollywood, Margate and Sunrise also were cut.

Block grants were created in the early ‘70s to help cities deal with insufficient local revenues.

At Miami City Hall Thursday morning, in front of hundreds of elderly people who count on the federal assistance for food and transportation, Mayor Regalado will bemoan his cash-strapped city’s plight during a press conference. The mayor hopes to get the ear of President Barack Obama, who will be across town at the University of Miami talking about the improving U.S. economy while campaigning for reelection.

The president, with an executive order, has the ability to leave Miami’s CBDG funding at 2011 levels. But that would require a Census Bureau finding that the 2010 count was flawed, as the city contends, and that a recount is necessary.