How to improve eating habits in a less-than-normal living arrangement?

Abount a month ago I joined a local gym and have been really good about going to work out 3-4 times a week (I'll go more frequently after I sell my house in a few weeks), but so far I'm not noticing any visual changes in my body. A big part of that, I know, is how I eat and that's where my problem begins.

I'm a volunteer with the local fire department and I'm actually "living" at the fire house (it's like a dorm situation except that we run emergency calls in the middle of the night). There are about 12 other live-ins, plus the career crews during the week and all the other volunteers that are there round the clock and we're all sharing 1 kitchen. With all those hungry folks (mostly the guys) keeping food that I've bought in the kitchen for more than 20 minutes is nearly impossible and going to the grocery store every day is tiring.

So I wonder if anyone has any bright ideas for how I can eat better without a kitchen at my disposal and without going broke.....