quick healthy transportable meals

[playguitar]

For the past week I've been in a show that involves a lot of dacing, singing, acting, and high energy levels every night for two hours. We've still got the rest of the month performing; but in this first week I've noticed I haven't been eating so well because I'm always out of the house right at dinner time and I end up eating a quick meal or snack before dashing from the house. I was wondering if anyone had any recommendations for energy-boosting, healthy meals I could make during the day (or days ahead), keep and heat up at the theatre with me so I'm still managing to look after myself whilst being so busy?
Please and thankyou!