Researchers from the University of Queensland have found almost half of all Australian families in a long-term study have experienced poverty at least once.

Emeritus Professor Jake Najman says the study, which followed families for 30 years, indicate it is common for families to slip in and out of hardship, mostly due to circumstantial changes such as relationship breakdowns and employment loss.

Professor Najman says the study found single mothers, the unemployed and elderly pensioners were the most likely groups to suffer poverty.