This question feels like it should be self-explanatory, but just in case it’s not, one of the biggest reasons why actors don’t bother eating the food that they’re given during each take is because there are multiple takes to many movies and TV shows. Imagine having to eat, and eat, and eat, until your stomach is rumbling since it’s full and you’re about to be sick simply because there’s only one of two ways that the food is going to go, out one direction or the other. This is why actors really need to become skilled at making it look as though they’re eating since some directors are such perfectionists that they’ll order one take after another and, as a result, if an actor has to pretend that they’re eating, there’s very little that they’re actually going to consume. If the actors are lucky, they might get the shot in a couple of takes and only have to consume so much before moving on. But for those that aren’t so lucky, it’s not much of a wonder why there are scenes in many movies when the actor loses their appetite or somehow just doesn’t happen to notice that there’s a plate of food right in front of them. Those are the people that get off easy since they don’t have to even bother trying to make it look as though they’re eating.
Quite a few actors will actually use a spit bucket between takes as well, and there are those that have revealed that a lot of the food, if not all of it, used on a movie set isn’t real. The food that doesn’t generally get touched might not be real, but even the stuff that the actors are meant to consume might not even be real. Keep in mind that in Splash, as seen above, Daryl Hannah’s character had to bite through a lobster shell, which you can imagine isn’t all that great for your teeth. But the trick with food in the movies is that the actors aren’t really eating much if any of it, as there are caterers and private chefs that take care of those needs. But while they might not be eating it, some of the ‘food’ might actually be fake, or it might be made of other stuff that can spoil under the hot lights since most sets have to deal with lighting needs that will require rather hot stage lights that might be needed to shine down on the sets for a while. Hot lights can tend to wreak havoc on sensitive foods that can’t sit under what is essentially a heat lamp for too long, so thinking that various items might need to be replaced now and again isn’t hard to believe, nor is the idea that some of the stuff might not taste that great.
There are likely times that some of the food is actually being eaten, as there are those movies out there that show people consuming things in a fashion that’s way too realistic to be faked, such as in Animal House, when Bluto stuffs a whole burger in his mouth. It’s fair to think that he spat that out after the take was done though, but the bottle of ‘Jack Daniels’ was actually iced tea, which can obviously be made to look like whiskey without too many problems. For those of you that thought he was really chugging a fifth of whiskey, sorry to burst your bubble, but even a raging alcoholic couldn’t be that convincing. But food in the movies is something that has to look every bit as real as anything else since otherwise there’s not a lot of point in having people sit down to eat or grab a bit while they’re on their way to one location or another. It does look convincing sometimes, there’s no doubt about that, especially when the character appears to be starving and is stuffing food into their mouth like there’s no tomorrow. But one has to remember that once the director says ‘cut’ a lot of those actors are probably going to be spitting out whatever is still in their mouth. Eating too much per take is bound to fill up the stomach and make it impossible to keep going after a while, though if one remembers all the articles about Brad Pitt eating during a take, they might have questions as to whether or not he’s really eating or if it’s always just a part of his character.
There might be times when an actor has gone without eating for a good part of the day and might actually need a bite to eat, which means during one take or another they might really be eating something. But it’s almost guaranteed that once they’re sated that they go right back to spitting in a bucket again.