Having surgery and will be in the hospital for one week and out of the gym for one month. What food should I eat to ensure I don't lose muscle? I'll probably be on pretty strong painkillers at the hospital so might not have much of an appetite. I'm thinking I need high calorie, high protein food to ensure I don't lose any weight. 

Also, I won't have a fridge at the hospital so unfortunately milk/cheese is out the widnow