Patients in Health Service hospitals are far more likely to go hungry than criminals in jail, scientists warned yesterday.
They say frail and elderly patients do not get the help they need with meals, and nobody checks whether they get enough to eat.
Despite years of Government promises to tackle poor hospital nutrition, food still arrives cold, and patients often miss out because meal times clash with tests and operations.
Meanwhile, prisoners are enjoying carbohydrate-rich, low-fat foods which in many cases are better than they would have been eating on the outside.
The Daily Mail has been highlighting the scandal of old people not being fed properly in hospital as part of its Dignity for the Elderly campaign.
Hospital meals are often taken away untouched, because they are either unappetising or are placed out of patients' reach.
The latest figures show 242 patients died of malnutrition in NHS hospitals in 2007 - the highest toll in a decade. More than 8,000 left hospital under-nourished - double the figure when Labour came to power.
The NHS throws away 11million meals every year, and many nurses say they are too busy to help the frail eat.
Earlier this year the Mail revealed that some hospitals spend less on meals than the average prison.
Ten hospitals spent less on breakfast, lunch and an evening meal than the £2.12 a day allocated for food by the prison service. One spent just £1.
hospitals do spend more than £2.12, prisoners end up better nourished than
patients, say experts from
Professor John Edwards said around 40 per cent of patients were already malnourished when they were admitted to hospital, but their condition did not tend to improve while they were there.
'If you are in prison then the diet you get is extremely good in terms of nutritional content,' he said.
'The food that is provided is actually better than most civilians have.
'There's a focus on carbohydrates, then there's the way they prepare the food, it's very healthy. They don't add salt and there's relatively little frying of food - if you have a burger then it goes in the oven. Hospital patients don't consume enough.
'And from the work we've done we know that people who sit round a table eat a lot more, but this doesn't happen in hospitals.'
His colleague, Dr Heather Hartwell, said fruit and vegetables were given out in hospitals 'but this doesn't mean it's eaten'.
While patients suffer due to a loss of appetite as a result of their illness, they often go hungry because there is no one to help them eat.
Dr Hartwell said once food was prepared, it generally hangs around waiting for porters to transport it to patients. Then it may be left on wards until it goes cold.
'Ward staff also don't actually know how much patients are eating because it is domestics who clear the trays away,' she said. 'This is an example of fragmentation in hospitals that does not necessarily happen in prisons.'
The research found temperature and texture are among the most important factors in patients' satisfaction with food.
It concluded lack of appetite due to a medical problem is probably the main reason for under-nutrition, but said hospitals can make improvements.
Liberal Democrat health spokesman Norman Lamb said: 'It's incredible that so many hospitals are failing to serve healthy meals. If prisons can serve good food then so can hospitals.'
The Department of Health said: 'The majority of patients are satisfied with the food they receive in hospitals, and we are working to improve services further.
'The Nutrition Action Plan, Improving Nutritional Care, outlines how nutritional care and hydration can be improved and highlights five key priority areas for NHS and social care staff to work with.
'We have also introduced the concept of "protected mealtimes" where all non-urgent activity on the ward stops, so that patients can enjoy their meals.'