Bait is right. there is more to the story. And with more than 25 years of Naval service, perhaps I can shed some light on this subject.
Enlisted members of the service are provided meals by the Government. This basically comes in one of two ways. The first method is - Rations in Kind - meaning, meals are provided for you either in a mess hall or mess tent, mess decks on a ship, or the ever popular MRE. Where a military dining facility is not available, and in other cases where authorized, a service member will receive a per diem payment, to pay for meals. If you are receiving per diem, and eat in a military dining facility, you will pay for the meal. I've done this many times.
What is happening with the hospitalized service men, falls into the examples above. Either they are receiving Per Diem and are being charged for meals, or they are receiving Rations in Kind and Per Diem payments are stopped.
I've seem situations kind of like this with some of my junior folks. We deploy with Per Diem (again, to pay for meals), and some guys eat on the real cheap and send the extra Per Diem money home to the family. The family gets used to the extra cash. Situation changes, we know have a mess tent, Rations in Kind are available and the Per Diem is stopped. No more extra money to send home. Family complains that Sailor Dads pay has been cut.