(Adds definition of relative poverty)
ROME, July 17 (Reuters) - The number of people living in poverty in Italy jumped to almost one in six in 2012 with families in southern regions hit especially hard, a report showed on Wednesday, highlighting the human cost of the country's longest post-war recession.
About 4.8 million, or 8 percent of the population, face absolute poverty, meaning they are unable to afford the minimum acceptable standard of living, the report from statistics office ISTAT showed. That figure jumped from about 3.4 million in 2011.
Overall, 9.56 million people, or 15.8 percent of the population, were living in absolute or relative poverty, up from 8.17 million people in 2011.
Italy measures relative poverty on a sliding scale starting with families of two, who fall into the category if their combined monthly spend is the same or less than the per-person average, which was just over 990 euros in 2012.
Poverty levels are especially high in the traditionally poorer south of the country, where almost one in three people face relative poverty and 11 percent are living in absolute poverty.
Poverty rates rose particularly among families with several children, while single people were less affected, ISTAT said. Levels were also higher among families whose main breadwinner is unemployed or a factory worker, or who include two or more elderly people.
A recession that has lasted almost two years has taken a heavy toll on ordinary Italians, hit by rising unemployment and purchasing power that has declined due to aggressive tax hikes aimed at strengthening public finances.
A report released by ISTAT in May showed that millions of Italians cannot afford to heat their homes properly, take a holiday away from home, or eat meat. (Reporting By Catherine Hornby; Editing by John Stonestreet)