One in 25 people in England cannot afford to feed themselves, research suggests.
Researchers mapped food poverty across England and identified Liverpool, Kingston upon Hull and Middlesbrough as the cities with the greatest number of neighbourhoods where people were at high risk of struggling with grocery bills.
Parts of Leeds, Manchester and Wokingham in Berkshire are among the areas with the lowest risk of food poverty, according to the study, which is being presented at the Royal Geographical Society's annual conference.
The risk of food poverty is highest mostly in urban areas outside London, according to the researchers from the University of Southampton, London School of Hygiene and Tropical Medicine, University College London and East Surrey Hospital.
Dr Dianna Smith, from the University of Southampton, said food poverty was on the increase in the UK but there was no robust way of measuring it, unlike in the US or Canada.
The presence of food banks was not a good measure of food poverty as the places they were found did not relate to the areas of greatest deprivation, but tended to be where there was capacity for them, she said.
The researchers used information from Government departments and the census to estimate the percentage of people who could not afford to feed themselves and modelled the distribution of food poverty in neighbourhoods across England.
The team, whose study is under review for publication in the journal Health and Place, hope the model will help local authorities and organisations respond to the problem.
"Pensioners living alone and families on a low income with children are particularly vulnerable to food poverty," Dr Smith said.
"In low income families struggling to feed themselves, free school meals is a crucial lifeline and 'holiday hunger' is a real concern at present. It's crucial that we are able to identify where support is most needed.
"The tools we have developed will allow for more effective local responses targeting high-risk groups in each area.
"We hope that they will help inform local interventions to address food poverty, such as community supermarkets or meals for local residents."