A couple ideas:

 Low fat bean burritos..Fat free beans low fat or fat free tortillas, with low fat cheese and all the fixings..even fat free or low fat sour cream...Very satisfing

 Im pretty picky when it comes to tuna fish I only eat the white tuna..I prefer it in the bag as opposed to the can. Also if you havent tried white meat chicken on the can or bag it's even better than tuna...I mix mine with mustard or red hot instead of mayo.

kmarcks .. may I be so bold .. are you Jewish ?

Anyhoo .. what about tuna, plain in a glad container, on a sandwich with whole wheat bread, hull out a tomato and fill the tomato with the tuna OR make chicken salad, make a wrap with a whole wheat tortilla with tuna, salmon, canned chicken breast.

While going through the grocery store yesterday I wanted some hummus .. couldn't find the brand I had a coupon for (Athenos I think) and the only brand I found is called Fountain of Health, Hummus, Chickpea Dip.  Tonight I had a snack craving .. so I grabbed this hummus out of the fridge and a whole wheat tortilla - THIS STUFF IS DELICIOUS !!

In the case of not being able to bring anything that isn't Kosher ... have you looked at some of the food items lately?  I think probably 80% of items now have a "K" on them or the "U" ... you can always bring matzo !!  (hmmm come to think of it - I wonder how much fat there is in that?)

Sher