While you are still on pain meds you may not have much of an appetite. Some light things like yogurt or cottage cheese may be enough. If you wait 'til the day before you head to the hospital, and buy the longest off sell-by date, they should keep well for you. Or if you have a shopper, they could pick up fresh groceries for you to have your fridge stocked when you come home.
Hugs and prayers going out to all of you with upcoming surgery.
Patti