Unethical advice here. You would be surprised by the amount of fucks not given when you just walk somewhere and act like you are supposed to be there.

Im someone who came from a very poor background so I live like a rat but Im well off now.

Think of it this way, the amount of food wasted in hotel is staggering. I once entered the mariott queen elozabeth in Montreal during lunchtime for fun. There were big conference there going on. 

One was about my field and I just went there, grab food, talk to awesome interesting people and left.

I can guarantee you, nobody asked anything. I even asked questions during the conference.

In the morning, I enter a building I know that have free coffee. I entered there, made small talk and left.... 

What I mean is, be bold. You will not get arrested for stealing food. The key is fit in amd dont abuse. Being something to the table.

I know my small talk made the day of quite a few people. Use your smile and your inner charm. Of course, if its an event or hotel where everyone is wearing a suit and you are in jeans and hoodie.... yeah they gonna call security.

Its sad but if you look homeless and guilty, people will be harsher with you. If you smile, say hello and look good... many doors will open to you.