WASHINGTON (Reuters) - Nearly one in five U.S. households ran out of money to buy enough food at least once during 2009, said an antihunger group on Tuesday, urging more federal action to help Americans get enough to eat.

“There are no hunger-free areas of America,” said Jim Weill of the Food Research and Action Center. Weill said he hoped President Barack Obama would exempt public nutrition programs from a proposed three-year freeze on domestic spending.

Obama has a goal to end childhood hunger by 2015. He backed a $1 billion a year increase in school lunch and other child nutrition programs a year ago.

Nationwide polling found 18.2 percent of households reported “food hardship” -- lacking money to buy enough food -- in 2009, according to the group. That is higher than the government’s “food insecurity” rating of 14.6 percent of households, or 49 million people, for 2008.

Households with children had a “food hardship” rate of 24.1 percent for 2009 compared with 14.9 percent among households without children. Twenty states had rates of 20 percent or higher. Seven Southern states led the list.

The figures were based on responses to the question, “Have there been times in the past 12 months when you did not have enough money to buy the food that you or your family needed?” The question is similar to one asked by the Census Bureau in collecting data for the annual food-insecurity report.