Around one in seven adults live in homes where people have skipped meals, reduced meal sizes or gone hungry, an online survey suggested.
Food has become more expensive as producers push their rising energy costs on to consumers.
Prices are rising by 7% a year in the UK - the highest rate for 30 years.
The Bank of England has warned inflation might reach 10% within months, as the rising prices of fuel and food put pressure on household budgets.
The Food Foundation also said that people had increasingly opted to take more cold food from food banks because of fears that cooking items would increase their energy costs.
The research by YouGov saw 10,674 adults surveyed online between April 22 and 29.
It found the number of people struggling to buy food has risen by 57% in three months.
Nearly 14% of survey respondents said they or someone in their household had eaten smaller meals or skipped meals because they were not able to afford it during the past month. This was up from 8.8% of the survey respondents in January.
Anna Taylor, executive director of the Food Foundation said the situation is "rapidly turning from an economic crisis to a health crisis" which food banks should not "possibly be expected to solve".
"The government needs to realise the boat is sinking for many families and it needs to be fixed. Bailing out with emergency food parcels is not going to work," she added.
A government spokesman said: "We recognise the pressures on the cost of living and we are doing what we can to help, including spending £22bn across the next financial year to support people with energy bills and cut fuel duty.
"For the hardest hit, we're putting an average of £1,000 more per year into the pockets of working families on Universal Credit, have also boosted the minimum wage by more than £1,000 a year for full-time workers and our Household Support Fund is there to help with the cost of everyday essentials."
Shadow work and pensions secretary Jonathan Ashworth said: "These are devastating findings that reveal the acute levels of hunger impacting families and children nationwide caused by the Conservative cost-of-living crisis."
Prof Sir Michael Marmot, director of the UCL Institute of Health Equity, said the survey's findings suggest society is "failing in a fundamental way".
"These figures on food insecurity are all the more chilling because the problem is solvable. But, far from being solved, it is getting worse," he added.
Sky's Paul Kelso takes you through the spike in household energy costs and explains why the cap continues to rise.