The exception to meals not being provided at the studio is on sitcoms. Sitcoms are filmed once a week before a live audience. Most of the cast and crew on a sitcom work throughout a typical week rehearsing the scenes and blocking the cameras. Extras are usually there only on the day of the live taping, but sometimes can be there on other days if they're an integral part of a scene and need some rehearsing also. A hot meal is catered and served to the cast, crew, and extras on the day of the live taping within an hour or two of when the show is to begin.
Meal breaks are to be provided after a maximum of each six hours of work.
Usually they go the maximum six hours before breaking for a meal. On particularly long days of shooting, there may be two meal breaks. On the day I worked from 5AM till 1 AM the next morning there were two scheduled catered meals, an NDM breakfast and lunch. When the day ran so long that they needed a third meal break and no caterer had been scheduled, meals were purchased at a nearby fast food chicken place. On other shows that ran longer than scheduled, food such as pizza and Subway sandwiches were provided.