Would be a waste of money time and lives to start charging for food. People wont heal/recover if they are skimping on their food to avoid a bill!
Last time I was in hospital, a couple of years ago, I can only thank heavens it was for 24 hours, as the food supplied was truly diabolical. Breakfast was a cup of weak tea and one slice of toast, meagrely spread with margarine. Dinner was a one egg omelette, and 3 small boiled potatoes, followed by a small pot of jelly. Tea was a limp cheese sandwich and a weak cup of tea. I wouldn't call that a diet designed to aid healing and recovery, would you? I would willingly contribute financially in order to be better fed.