You should ask them for the food they're about to throw away, too.
I did, back when I was homeless and doing the change thing and things got pretty desperate. Most places stated that doing so "would be a liability" which is laughable, because they could have sold me the same food. I also had to wait until the office closed at the storage unit I was renting (and secretly sleeping in) so I could sneak out, so a lot of places were already closed.
McDonald's will always be my hero for that period of time in my life. One night, in desperation, I jumped on the sensor at the menu board until it registered that I was there. They took my order, and when I got to the window they almost turned me away. I insisted that I was in a car, and was a time traveler from the future who was driving an invisible car. I did it in a way where it was clear that I wasn't serious, but was seriously hungry, and made them laugh to boot. We shared a real moment where it came out that I was homeless. They told me that they couldn't give me the food in the window because of cameras, but to go up to the door. The manager came out with two bags full of food despite me having ordered/paid for two $1 McChickens and a large drink. I hugged the crap out of him, then snuck back into the storage place and ate like a king. From there on out, they were cool about me driving my "invisible car" into the drive-thru (in moderation) and always threw some extras in. Luckily I was couch-surfing at a friend's house after about a month, so it didn't happen often/long enough for any issues.
Just in case I need a disclaimer: I know it's illegal to sleep in a storage unit. I was a paying customer and basically non-existent there except to sleep on my bags of clothes, and used my phone for light rather than candles or electricity. It was a really bitter late Autumn/early Winter, so it was better than freezing in the streets.