The growing demand for food banks is "inextricably linked" to welfare reforms, charities have told MSPs.
Thousands more people have turned to voluntary organisations for emergency food parcels, following changes to the benefits system that were introduced by the UK Government last April, the Scottish Parliament's Welfare Reform Committee heard.
Those who rely on food banks often walk for miles because they cannot afford to pay for transport, and many are given items that can be eaten cold because they are unable to pay for electricity to cook, the committee heard.
The services are also being used by people who are employed on low incomes, and who are struggling with the rising cost of living, the charities said.
The Trussell Trust has reported its food banks helped more than 56,000 people between last April and February 24. The total for the previous 12 months was 14,318, including about 4000 children.
Ewan Gurr, the charity's Scotland development officer, said: "That is an exponential rise in the demand for emergency food relief.
"It is indisputable that people are under more pressure than they ever have been, and obviously we are not seeing benefits keep pace with the rise in living costs.
"The evidence we are seeing every day right across our food bank network is that welfare reforms are inextricably linked to the rising demand for emergency food relief."
Jo Roberts, of Community Food Moray, said the organisation saw about 13 cases each month before last April. After the introduction of welfare reforms, this number grew to 59. The charity recorded 301 cases last month.
"The main issue people are presenting with is welfare and benefit problems. The biggest reason is welfare sanctions," said Ms Roberts.
She said demand for "cold food boxes" was increasing.
"On our referral forms we ask what cooking facilities people have. We have a number coming through where, yes they have all the cooking facilities, but they can't use them because they can't afford to put the electricity in the meter," she said.
Problems with transport are also an issue, Ms Roberts added.
Denis Curran, chairman of Loaves And Fishes, a Glasgow-based charity that provides food parcels, agreed people were "walking three or four miles with children" to attend food banks.
SNP MSP Annabelle Ewing said she had met someone who walked about 12 miles from Ballingry to Dunfermline to access a service. "I think the issue of transport is hugely important because many of these facilities are not going to be on the high street," she said.
Mr Curran also highlighted misconceptions about why people are using food banks.
"There seems to be a fallacy out there that it is misused, and that it's greed," he said. "It is easier to say they are thieves, liars, cheats and layabouts, that they misuse the benefits system.
"What is the real figure of the people who have committed suicide through benefit cuts? People come to us and they are terrified.
"Powers that be, it is time you woke up to reality. We do not need meetings to decide if benefit cuts have got something to do with a rise in food banks.
"The situation is people are being penalised for being poor."
Dave Simmers, chief executive of Community Food Initiatives North East, called for more research into the scale of the issue.
He said: "Anecdotally we have strong evidence of the impact of welfare reform on the usage of food banks but, undoubtedly, there is a need to back that up with independent research."