Parents across Australia are keeping their children home from school because they can't afford to put food in their lunchbox, new research shows.
A report released on Tuesday by Anglicare Australia estimates around 45,000 households using its emergency relief services don't have enough money to adequately feed their families.
Of those, adults in nearly 22,000 households were not eating for a whole day at least once a week.
One in 10 households also reported that children went without food for 24 hours on a regular basis.
"It just seems unthinkable in 2012 in Australia," Anglicare's executive director Kasy Chambers told AAP.
"We think being hungry is pretty horrible, but it means that people aren't going to school or they're going to school hungry.
"It means that families aren't going to community BBQs, they're not having friends around, their kids aren't having other kids to visit.
"It's excluding people, it's taking people out of those connections."
Ms Chambers said her organisation had been told "heartbreaking" stories of children being bullied because they didn't have food, while their parents were so embarrassed about their struggle they refused to invite people to their house.
The report found 94 per cent of households with food insecurity were also suffering rental stress.
Most relied on government support payments like Newstart and had little to no money left for food after paying rent and other necessary bills.
"If you think that you might not be able to feed your family at some stage over the next week, that does start to eat through your wellbeing," Ms Chambers said.
Australian Greens senator Rachel Siewert, who launched the report in Sydney, said widespread food insecurity among people on income support had broad impacts on getting people to work and children's education.
"Forcing people to live in poverty has detrimental impacts not only on their health and wellbeing but on their ability to find work," Senator Siewert told AAP.
She said increasing the Newstart allowance by $50 a week would make a "significant" difference to these people.