You'll save a lot of money and you'll eat better. I like the salads in a mason jar (google it and you'll find 10,000 Mormon mommy blogs that explain what they are). Sometimes I put meat (grilled chicken or steak) in the salad, sometimes I bring a tupperware of some meat with me to eat separate.
The salads are make-ahead, so you can make 5 on Saturday or Sunday and stick them in the fridge and just take one a day. My wife takes all five to work on Monday so she doesn't have to worry about forgetting in the morning.
As for leftovers, after a meal is done and I'm cleaning up the table, I pack at least two or three individual meal sized tupperwares of food. Sometimes I divide all leftovers into individual sized containers, sometimes I have a big one that I crack open if we're going to reheat leftovers for another dinner or I want something on Saturday or Sunday for lunch. Dividing the leftovers when to first store them makes taking them for lunch easy---you just have to open the fridge and take one tupperware with you without trying to open something, find a container, take a portion, and then go.