A United Nations investigator said the government should not rely on organisations like foodbanks "to keep people alive".
During a visit to Newcastle's West End foodbank, Philip Alston said the foodbank's users were "under a huge amount of pressure".
The UN special rapporteur has been on a fact-finding trip to the UK.
The government said it had lifted hundreds of thousands of people out of poverty and into work.
Mr Alston, whose work focuses on extreme poverty and human rights, said foodbanks play "a really crucial role... that real safety net so that [people] don't quite starve".
But he said it should be the government that provides the safety net.
"You risk sending the message that government doesn't need to play the central role and government can just outsource these things," he said.
It cannot "just hope that a private community is going to take it up and keep people alive", he said.
The West End foodbank feeds about 42,000 people every year and has been giving out about 20% more food than six months ago, according to the Local Democracy Reporting Service.
One of its users, Denise Hunter, said: "I've now waited for months and months for Universal Credit.
"Without these people here, with the free meal and everything, I couldn't live," she said.
Her 20-year-old son, Michael, said Universal Credit had "tipped us over the edge" and that he regularly goes hungry.
"We've been living where we're scared to turn the heating on because it eats electric or, if you turn the oven on for cooking and have it on too long, we can't pay the bill," he said.