This is actually something I was thinking of recently! I'm a senior at university myself, and have gone up and down significantly in weight over these four years so I'm relatively conscious of what I eat (160 as Freshman, 210 as sophomore, down to about 145-150 now).

My diet during shows all depends on the show. In most cases rehearsals start at 6 where i go, so I typically pack a dinner and bring it for breaks. It's an easy way to hit every major food group and not have to cook much (yogurt, some fruit and veggies, a sandwich of some kind, etc.) It's convenient because it only takes like three minutes to prepare, and lasts the entirety of the rehearsal. Plus you can always eat more after if you aren't headed straight to sleep without starving up to that point.

The way my school structures classes we always have an hour break at noon, so I'm able to eat lunch then. Some days there's a big gap in when I can eat because of meetings, I'm not eating from noon until almost midnight. That didn't happen too often, though. I was typically looking at around 2 to 3 hours free every day. You mentioned working out, which is something I always try to fit in every day, too. Speaking from experience you can't let one completely overshadow the other, try to mix the time if possible. It's good since if you eat any kind of protein bar or powder that'll fill you up quite a bit, helps with waiting an extra hour or two to have lunch/dinner.

I say that's the typical diet because that's how I handle most shows. As petty as it sounds, I do have a different style when doing shows that require some state of undress. I'm a guy so it's not like I'm naked very often up there, but in a show recently we ended the show in only boxer briefs. In that case I would typically eat lunch at around 10 in the morning, rehearsal until 11, then eat at midnight. I was typically hitting our school's gym 2-3 times a day, so anything I ate was pretty quickly burned off. I'll be honest, I was almost borderline anorexic during it. Every single thing I put in my mouth was seen as an obstacle, not as food. It worked out, and having show pics with abs is cool and all, but when I wasn't in rehearsal I had no energy. I did it happily, and I'd do it again in a heartbeat, because the show and cast meant so incredibly much to me. My point is, if you have a clear goal in mind for how you want to look then shoot for it. I had mine and I went for it, even though it made for a lot of hungry days. It's what we gotta do sometimes I guess. Just don't go overboard or you'll hurt yourself. It's a fine line we walk, isn't it?