It takes a little planning to figure out how to pack and how much fits in the cooler. I've got it down to 2 sandwich size tupperware containers for somethign like a meat (chicken, ground turkey, tofu) and a spinach salad and some brown rice mixed in with some zero fat/carb dressing and the other is usually tuna (albacore in water, drained) w/ mustard and broccoli, all of that covered in zero fat/carb honey mustard dressing. If I eat it cold, I can pre-mix a teaspoon of flax oil in it. If I nuke it before eating, then I'll carry a plastic bottle of flax oil in the cooler. If I want some change from brown rice, I also pre-slice about 3 oz sweet potatoe and nuke it at work. Only use pepper as seasoning. I also carry a plastic bottle w/ a top (not the kind w/ the straw -- too hard to keep clean) and a baggie w/ pre-measured zero carb Isopure protein mix + l-glutamine already in there. Just dump it in the plastic bottle and mix in some water. I also carry one of those nice little bottle shaped cooler things that you zip up the big bottled water in and it has a strap. I kill about 3 of those /day. I will also carry an extra apple, another baggie of protein mix and maybe a protein bar if I have to work late or start starving at some point. I keep back up oatmeal, tuna, mustard & diet coke, along w/ my Ripped Fuel, of course, at work. I've also premade scrambled egg whites maybe with some ground turkey or that soy burger stuff, along w/ some brown rice & tamari sauce or soy sauce (low sodium), and nuke that at work.
Then I also have enough room for 2 of those freezer packs so I don't have to keep it all in a refrigerator. This way I'm completely self-sufficient all day. I pound down my oatmeal & egg whites or protein mix before I go to work.
Its not exciting but it works for me!