I work 12 hr overnight shifts @ the hospital & what works for me is bringing a portable cooler--big enough to hold 6 bottle drinks--each night I work. It has 2 zippered compartments. Instead of a purse, I bring a backpack.
Food I bring: PB2 Greek yogurt, granola, instant coffee, Splenda packets, 100 cal microwavable popcorn, small salads, dressings, soup, fruit, sandwiches, cheese slices, Rye crackers, trail mix, assorted nuts, yogurt raisins, Cottage Cheese. (Not all the same night, I mix it up)
I also bring a Diet Coke and 3 bottles of water. (2 of the bottles of water go into the backpack and are placed in the cooler when I drink the one that has chilled.)
Planning is really the key. It's easier to go to the cafeteria or order take-out with everyone else, but I find this hinders my fitness goals. When I chose to participate with my colleagues in this behavior, I was 167 lbs.
I try to keep portable food in my fridge for individual grab-&-go, like:
1/2 cup servings of fresh fruit, cottage cheese, greek yogurt (I use plain and add PB2, granola, and Agave), cut up fresh veggies.
I use Rubbermaid Take-A-Longs
products to store them in the fridge.
When I do not plan the day before and have to go to the cafeteria to eat or eat take-out, it is usually a disaster in cals, carbs, fat, & nutrition altogether.
Best of luck to you.
I keep all of this at the nurses station in the back. Nothing is left in the break room or the yucky break room fridge.