THE United States' economic crisis has raised the number of Americans who lack enough food to the highest since the Government began keeping records.

A report shows nearly 50 million people - including almost one child in four - struggled last year to get enough to eat.

At a time when rising poverty, widespread unemployment and other effects of the recession have been well documented, the report released by the US Department of Agriculture provides the Government's first detailed portrait of the toll the faltering economy has taken on Americans' access to food.

The size of the increase in food shortages and, in some cases, outright hunger, identified in the report, startled America's leading anti-poverty advocates, who have grown accustomed to longer lines at food banks and soup kitchens. The findings also intensify pressure on the White House to fulfil the pledge to stamp out childhood hunger made by President Barack Obama, who called the report unsettling.

The report shows that dependable access to adequate food has especially deteriorated among families with children.