For a growing number of Americans, retirement isn't about taking long-overdue vacations or spending long days in the sun playing golf; it's about scraping together enough money to pay for basics like food and housing.

The percentage of older people living below the poverty line has climbed steadily since 2005, according to a recent Employee Benefit Research Institute study. For Americans ages 65 to 74, poverty rates increased from 7.9 to 9.4 percent between 2005 and 2009. Among those ages 75 to 84, rates increased from 7.6 percent to 10.7 percent. Nearly 15 percent of the oldest retirees were living in poverty in 2009.

For many of America's oldest citizens, living below the poverty line translates into an empty belly. Over the last decade, the number of seniors experiencing hunger increased 80 percent, according to a new report from the Meals on Wheels Research Foundation. In 2010, more than one in seven skipped meals because of lack of money or expressed anxiety about not having enough food.

Eighty-eight-year-old Miriam Boss had to be hospitalized because she wasn't getting enough food. The retired retail executive from Philadelphia was feeling so faint she kept falling.

“I never thought anything like this would happen to me,” Boss told the Philadelphia Inquirer. “I have a daughter and grandchildren and great-grandchildren in Connecticut. They call me and try to make me happy, but they don’t know I’m hungry.

Failing health drives poverty among the elderly, according to Employee Benefit Research Institute. Seventy percent of retirees who have fallen on hard times have suffered acute health conditions like cancer or heart problems, compared to 48 percent of those who live above the poverty line. Similarly, 96 percent of impoverished senior citizens have some sort of health condition, such as diabetes or arthritis. The same is true for just 61.7 percent of their wealthier peers.

"Medical expenditures go up for the elderly as they age and medical expenses have been rising over the past decade very rapidly," Sudipto Banerjee, a research associate at EBRI and author of the report, told U.S. News and World Report. "A lot of people have to move to nursing homes, and nursing homes are very expensive. People who live there, they lose their income and assets very quickly."

Because of the recession, many retirees spent their retirement savings too quickly, Banerjee said.

"I would expect as the economy does better, the rates will go down," he said.