More than 4 million children are living in homes without proper access to food, according to grim new figures.
Analysis for the Food Foundation found that one in four (26%) of households with children experienced food insecurity in September, such as skipping meals, eating less, or going hungry all day.
The situation has worsened in the past six months as cost of living pressures mount - with 2.6 million children living in homes where they struggle to get enough food in April.
Overall, nearly 1 in 5 (18%) households were unable to afford or get food last month - amounting to 9.7 million people. In April the figure was 7.4 million.
Brits who have experienced food insecurity in the past month said they have cooked less, eaten food cold, turned off fridges or washed up using cold water.
Some 58% said they were buying less fruit and 48% said they were reducing the amount of vegetables they buy.
More than half (54%) of families on Universal Credit are struggling to get enough to eat, the survey found.
The grim findings fuel mounting calls for an expansion to the free school meals scheme to help families struggling with spiralling food and fuel costs.
The Mirror and the National Education Union (NEU) are calling for all primary school kids in England to get access to free dinners - in line with commitments in Scotland and Wales.
All young children in England can get free school meals up to the end of Year 2 but after that it only applies to households on certain benefits.
Children living in Universal Credit households can only get the benefit if their parents earn less than £7,400-a-year from work.
The Food Foundation urged the Government to widen the scheme to all UC households and to keep Boris Johnson's promise to lift benefits in line with inflation in April.
Retailers must also step in to keep costs down and make healthier options affordable, the organisation said.
Anna Taylor, Executive Director, the Food Foundation said: "There are very serious physical and mental health implications from these worsening trends.
"It is hard for people who have never had to worry about having enough food to understand what it might feel like and we’re continuing to call on the Government to make this a priority."
Gwen Hines, Save the Children UK chief executive, said: "No child should struggle through the school day because they are hungry.
"Yet, right now, 800,000 children living in poverty do not have access to free school meals and are missing out on healthy, nutritious food. Clearly, this is unacceptable and excludes many children from getting what could be their only hot meal of the day.
"The current £7,400 household income threshold to qualify is far too low and excludes families who are really struggling. Extending free school meals to all children whose families receive Universal Credit is the right and fair thing to do."
Kevin Courtney, Joint General Secretary of the National Education Union, said: "This confirms what our members have been seeing in schools for months: that this Government is plunging more families into insecurity and at an alarming rate.
"The 50% increase since April 2022 in the number of children living in food insecure households should be alarming enough for the Government. If they don’t get a grip and take action, then millions of children will go hungry this winter."
Lynn Perry, Chief Executive of Barnardo’s, said: "The cost-of-living crisis is increasingly frightening for vulnerable families, with children at risk of going hungry, living in cold homes and missing out on everyday essentials.
"This new data from the Food Foundation highlights the scale and severity of the challenge and underscores the need for urgent action."
A Government spokesperson said: "Our priority will always be to support the most vulnerable and we recognise that people are struggling with rising prices which is why we are protecting millions of those most in need with at least £1,200 of direct payments.
“In addition, vulnerable families in England are being supported by the Government’s Household Support Fund – which was boosted by £500million - to help pay for essentials, and latest figures show that there were 200,000 fewer children in absolute poverty after housing costs compared to 2019/20.
“We have also expanded access to free school meals more than any other government in recent decades and we are investing up to £24m in our National School Breakfast Programme, which provides free breakfasts to children in schools in disadvantaged areas.”
