My answers when someone asked a similar question a little while ago:
* Home made protein bars/slice with oats, oatbran, egg-whites/eggs, protein powder, applesauce, cinnamon and nut butter (roasted almond) can make pretty tasty and easily portable bars.
* Make up some 'meal patties' and store them in the fridge/freezer - simply combine some ground meat of choice (chicken, tuna, salmon) and carb of choice (mashed sweet potato, chick-peas or lentils work well) with some eggwhites (for binding) and some seasoning (black pepper, spices, garlic). Then form it into patties and bake, grill or dry-fry until golden. Then just let them cool and store them in the fridge so you can just grab one and go.
* Pre-make meals in containers - Just combine tuna/chicken/eggs and beans/sweet potato/barley/rice (basmati, brown or wild rice) and some steamed vegetables in tupperware containers!!
* Pre-made protein pancakes can be used in the same way - just use ground oats (or oatbran), eggs/egg-whites, protein powder and cottage cheese (there are numerous recipes around) and pre-make a whole batch then seal them in an air-tight container in the fridge. They will usually keep for a few days.
* Fruit and fat free yoghurt tubs are easily!! Just combine sliced fruit/berries, yoghurt, cottage cheese (and some oats if you want) and away you go.
* Small tins of legumes (chick-peas/kidney beans) are simple and easy. Open the can, drain, combine with a can of tuna and you have a simple carb/protein meal.
* Use a shaker bottle to make 'protable milkshakes'. Simply put some protein powder in the bottom and take a tub of fat-free yoghurt. When you want a meal, add the yoghurt to the shaker, add some water and then shake it up. Little 'poppers' of long-life skim milk are easy to carry around for the same purpose as well (you could also use dry skim milk powder in the shaker with the protein powder).
* serving of nuts (walnuts are best ) and a 'no mess' tuna pouch packet with a fork. Gives you a quick and easy meal.
* Whole tubs of cottage cheese are great! A 250g tub is ~ 1 cup worth (and about 250 cals) and if you add 1-2 tbs peanut butter/ almond butter (another 120-240 cals) you have a 'meal in a tub'. You could add some psyllium to increase fiber.
* Hard boiled eggs
