I’m a little confused.
1. If you’re going alone or with your family to eat, then who will think you are hanging out with the crowd that happens to be there?
2. If your with your friends, but you plan on going to eat, and not talk with them, then people will still assume your hanging out with them, cuz you are.
If you are doing #2, obviously people will assume you’re there with the rest of the people, cuz you are.
If you do not want to be part of it, but you’re hungry, go to a non-hangy place or with one friend or sister. (Sadly, most people will not give you the benefit of the doubt.)