Food poverty in the UK has now become such a big problem that it should be seen as a "public health emergency", a group of health experts says.
In a letter to the British Medical Journal, six leading public health figures warned poor nutrition could lead to a host of problems.
It comes amid reports that people are struggling to feed themselves.
The UK Red Cross has started asking for food donations for the first time since World War Two.
And in October the Trussell Trust, which runs 400 food banks, said the numbers of people it was helping had tripled to 350,000 in the past year.
The letter also cited research from the Institute for Fiscal Studies that indicated the amount of money being spent on food by households had fallen by over 8% in real terms over the past five years.
Families with young children have been hit the hardest.
The study also suggested that much of the savings had been made by people buying cheaper, processed food.
The BMJ letter, signed by academics and pubic health directors, said this had "all the signs of a public health emergency".
It warned malnutrition, particularly during childhood, could have lifelong effects including increasing the risk of cardiovascular disease and other chronic illness.
David Taylor-Robinson, a population health scientists at the Medical Research Council and one of the authors of the letter, added: "It is clear people are increasingly struggling with their food bills.
"We need to start monitoring this and treating it as a public health problem."
Chris Mould, the executive chairman of Trussell Trust, said he wanted the government to set up an official inquiry because "these alarming developments point towards serious trouble for the nation in the years ahead unless urgent action is taken now".
But a government spokesman said action had been taken to help people with the cost of living, including increasing the tax-free personal allowance and freezing council tax and fuel duty.
He added: "The benefits system supports millions of people who are on low incomes or unemployed and there is no robust evidence that welfare reforms are linked to increased use of food banks."
By Nick Triggle
Health correspondent, BBC News