I always keep a slim fast bar in my purse for days I don't get a lunch at all. They don't taste good at all, but they're somewhat filling. I'm a stenographer, and often the attorneys/judges like to "work through lunch" without a real break. Sometimes they'll give me five minutes to rest my hands, so I need to wolf something down in five minutes.
Something I would suggest that's even better is to make a loaf of bread on the weekend with a fruit and/or veggie and add some walnuts to it (I like a hearty, sweet zucchini bread the best). I also do this with muffins. I find it much more filling and healthier than a meal bar. I can just cut a slice and wrap it in plastic wrap, or just grab and muffin and toss it in a little ziploc bag in the mornings. Plus, I have a healthy snack if I'm home, too
Good luck!
Lysne