At the Olympic Park and at venues across the city or Rio de Janeiro, the same menu is available for concessions featuring some basic sandwiches, a hot dog, among other things, all for about $4 or $5. (Although for some reason, I’ve come across more than a few that only seem to have peanuts available…)
To get that food, though, you first have to wait in a line to order it, getting a ticket that you then use to go into another line to pick up what you ordered. And at the Olympic Park in particular, those lines both in the common areas and in the venues are exceedingly long. People seem good-natured about it all, but if you’re hungry at the Olympics, you better be prepared to wait.