In the beginning, eating in a Primal manner will require planning. Once you're in the groove, you'll be doing it as easily as you once did SAD.
"Right is right, even if no one is doing it; wrong is wrong, even if everyone is doing it." - St. Augustine
Another option (something I plan to start on ASAP as I'm quite pregnant and don't forsee an intense desire to cook for awhile after giving birth) is to prepare your meats/veggies/recipes - don't cook them, just chop up (or don't) and season, and store them in the freezer in big gallon bags or whatever you'd prefer to use. Then you can grab a bag 'o meal the night before you want to use it and stick it in the fridge to defrost, and put it in a crock pot the next day if you've got one, or throw it in a pot on the stove for an hour. (Add water or stock and you've got soup instead of stir-fry.) Boom, dinner! You could theoretically cut up and use the same kind of meat/vegetables on Sunday that you end up using for all your meals and have completely different flavor profiles depending on how you season.
I just make my own version of Lean Cuisine. I cook about four meals (meat, tomato sauce, 2 veg), pack them into Ziplock compartment plastic lunch containers, and freeze them. If your office has a microwave, then you just heat them for 5:50 and it's lunch.
5'0" female, 43 years old. Started Primal October 31, 2011, at a skinny fat 111.5 lbs. Low weight: 99.5 lb on a fast. Current weight: skinny-fat 106.5 lbs because of sugar cheating.
MY PRIMAL: I (try to) follow by-the-book primal as advocated by Mark Sisson, except for whey powder and a bit of cream. I aim for 80-90 g carb/day and advocate a two-month strict adjustment for newbies. But everybody is different and other need to tweak Primal to their own needs.
I do weekly batch cooking. If I know something is not going to be used until later in the week I usually freeze it. I break foods down into smaller batches (like chili or tomato sauce) and throw in the freezer. Foods like chicken legs, hamburgers, etc I keep in the freezer and just defrost as needed.