If you work outside of the home full-time, then you are faced with eating a few meals/snacks outside of the home everyday.
Having a good sized lunchbox/cooler is a great place to start. Be sure to get cold packs to insure that your food stays fresh.
Packing lunch for yourself is a bit time consuming, but very worth it. Not only do you know where your food came from, but you also know who prepared it and how.
Preparing in advance saves a lot of time. I think a great way to save time, is to cook extra when preparing food. If you are making chicken for dinner, cook an extra chicken breast or two. If you are having homemade chili, be sure to bag some up and freeze it for later. Or to save time you can prepare a few things on Sunday night. Prepare a few chicken breasts, wash, cut and separate your vegetables and fruit (cut produce will only last a day or two), prepare your homemade trail mix and divide out into single portion bags, hard boil eggs for the breakfast and snacks all week long...there are many things you can do in advance, in an effort to make packing healthy snacks and meals for the week easier. Not only will it help you to eat healthier, but it will also help save you money not eating out everyday.