Some 11,515 children and adults have been admitted to hospital with malnutrition since 2015, according to research by an MP.
Data also shows there were 2,483 hospital admissions of children and adults due to malnourishment between January and June this year, according to Freedom of Information responses from nearly 50 hospital trusts in England.
Liberal Democrat leadership hopeful Layla Moran, who collected the data, said she was "shocked" at the figures - which are equivalent to 103 hospitals admissions per week.
Hunger has surged during lockdown with government figures revealing as many as 7.7 million adults cut down on portion sizes or missed meals because they could not afford food.
Meanwhile, there has been a dramatic increase in foodbank use - with those operated by charity the Trussell Trust handing out 89 per cent more food parcels in April compared to the same month last year.
Over the past five years, 915 cases of malnutrition in adults and children have been logged at the Cambridge University Hospitals trust, while the Sheffield Teaching Hospitals trust reported 587 overall cases.
The Liverpool Women's Hospital trust reported a case of malnutrition in pregnancy, while the Royal London Free trust and Newcastle upon Tyne Hospitals trust both recorded 656 overall cases in 2020.
Some 80 NHS trusts responded to the Freedom of Information request, while only 50 provided substantive information, according to the MP.
Commenting on the data, Ms Moran said: "Today, in the UK, thousands of friends, relatives, neighbours and colleagues are at risk of the effects of malnutrition.
"These figures shocked me and make me angry that in Britain, in 2020, people can be hospitalised due to malnutrition.
"We need to move forward and create a system of social security that helps everyone and makes sure no one goes hungry in our country.
"The reasons for fixing this silent crisis are stark. Malnutrition and mortality are usually closely linked.
"Malnutrition lengthens hospital stays, reduces quality of life and increases the risk of developing other diseases."
Additional reporting by PA.
- An earlier version of this story stated that, in the last year, 915 cases of malnutrition had been logged by the Cambridge University Hospitals trust, along with 587 at Sheffield Teaching Hospitals trust, and 656 at both Royal London Free trust and Newcastle upon Tyne Hospitals trust. These were in fact figures for the last five years. The article has also be amended to clarify that the data related to all admissions for malnutrition, rather than just children. We are happy to make this correction.