Clueless about healthy dorm room snacks...Need help!?

I was pretty health conscious person ...I ate healthy .I drank green smoothies .I know what's good for me and what's not However since coming to college I was eating crap out of bags 3+ times a day. I'm still in the process of getting back to my earlier eating habits and i've been doing pretty ok so far . .the only thing that I cant help is snacking in the night ...my roommates have eaten nothing remotely healthy their whole lives and seem to know nothing about health or nutrition but manage to stay slim ...The thing is they eat large bags of potato chips in the night and I cant help myself and eat with them . I'd like to have something tangy and crisp to munch at night as well . I know lots of people on here are going to suggest fruit which I already snack on but there's only so much fruit one can eat . I'm trying to lose weight so I doubt nuts and dried fruit will help . I was thinking of popcorn . I have no idea if popcorn is healthy . Is it ? Doesnt seem like it when I look at the act II popcorn sashes . They seem to be full of oil . I'm really confused ...Are there any other alternatives ? HELP!