The number of people receiving emergency supplies from Trussell Trust foodbanks has more than quintupled since the coalition took power, according to new figures.
Over the last financial year 346,992 people received three days' worth of emergency food compared to 61,468 in 2010/11, a report by the charity said.
It warned the sheer volume of people needing help was a "wake-up call to the nation" and claimed the impact of welfare reforms that came into force this month have already sparked a fresh increase in numbers passing through their doors.
Of those helped over the last year 126,889 were children and most recipients were working-age families, according to the Christian charity.
Its research found 30% of people helped were referred as a result of benefit delays and 15% because of benefit changes. Overall, the charity helped nearly 100,000 more people than it had anticipated.
Foodbank recipients are referred by doctors, social workers, schools liaison officers or advisers at the CAB and Jobcentre Plus.
The Trussell Trust said its figures "do not represent discreet individuals as some people will have experienced more than one crisis in a year" but added it was the charity's policy to limit support to three crises annually unless there are extenuating circumstances.
Chris Mould, the charity's executive chairman, said: "The sheer volume of people who are turning to foodbanks because they can't afford food is a wake-up call to the nation that we cannot ignore the hunger on our doorstep.
"Politicians across the political spectrum urgently need to recognise the real extent of UK food poverty and create fresh policies that better address its underlying causes.
"This is more important than ever as the impact of the biggest reforms to the welfare state since it began start to take effect."