It's really, really important to consider what you're going to be eating for lunch and how that lunch is going to affect the rest of the day, the afternoon, into the evening. When you work out is obviously going to play a part in quite possibly what you might eat for lunch, but lunch is, again, one of the very, very important meals of the day. As far as lunch specifically, you want to consider how your body responds to certain types of carbs and proteins and so on so that you make sure your body's going to be energized after lunch and not have a drop.
For instance, when you think about lunch, remember that lunch is not happening in a vacuum or in a bubble because you're also going to have hopefully an early morning snack, or a mid-morning snack, and then you're also going to have an afternoon snack. So if you're having snacks on both sides of lunch, lunch doesn't need to be this huge meal that's going to just fill you up with lots of calories that aren't going to go anywhere. Make your snacks healthy on both sides of lunch, and make lunch maybe a little bit leaner and lighter.
Lunch should also be the same thing as your other meals - healthy forms of lean protein, complex carbohydrates. Grilled chicken salad - you may be someone who needs a little bit more than lettuce because your body responds differently to certain kinds of carbs. You can have higher glycemic carbs and do well. So you may want to have chicken and yams or you might want to have a grilled chicken on a multi-grain wrap or multi-grain bread so you're bringing in the complex carbs and the proteins - turkey burgers, lean cuts of meat, or even fish are good.
But again, watch portions at lunch time because you want to balance your calories. You're getting calories from lunch, but you're getting calories from breakfast, you're getting calories from dinner, you're getting calories from your snacks, you're getting calories from your post-workout nutrients and shakes as well. Hopefully you're also incorporating a pre and post workout shake. That's also going to give you more calories, so you need to base all this on the understanding of a healthy meal plan that's going to have you eating at least five, six, seven meals a day and then spacing those calories out.