The shocking impact of recession and austerity on England’s poorest people has come to light again in figures showing the number of malnutrition cases treated at NHS hospitals has nearly doubled since the economic downturn.

Primary and secondary diagnoses of malnutrition – caused by lack of food or very poor diet – rose from 3,161 in 2008/09 to 5,499 last year, according to figures released by the health minister Norman Lamb.

While the data does not include information on the circumstances of each diagnosis, the rise coincides with a dramatic increase in the cost of living, and a spike in demand for charity food hand-outs.

The figures, broken down by region, reveal the heaviest burden of hunger is being felt in rural areas. Hospitals in Somerset saw the most cases, with 215 diagnoses, followed by Cornwall and Scilly Isles.

Hospital statistics represent the number of admission episodes, not the number of patients, so the figures may represent some repeat visits. But Jim Cunningham, Labour MP for Coventry South, who acquired the figures in a written answer to a parliamentary question last week, said they were a “map of how the economic situation of the past five years has affected people”.

“We have seen high-energy prices, the bedroom tax and a growth in organisations helping people who can’t afford food – and now this,” he said. “With diminishing resources for the NHS, they could do without a situation like this.”

In another indication of food poverty’s growing impact, figures from the Health and Social Care Information Centre show that diagnoses of rickets – a disease of poverty associated with vitamin D deficiency – have also risen significantly, from 561 in 2008/09 to 702 in the past year.