What do you all suggest would be a good way for me to "eat smarter"?

I am a grad student who has a meal plan but no kitchen (only microwave and small fridge). I know that not having junk food in my room is good, and I avoid that as best I can. All the suggested meals I've seen consist more of things I would have to make than meals I could buy or get in the dining hall.

Trying to work off the undergrad weight gain.