As a follow-up to the pregnancy question, what about post-pregnancy? What can I expect for additional calories if I am breastfeeding?

It's breast-feeding where you're really burning the calories.

When you're breastfeeding full time, you'll need an extra 500-600 calories each day to feed your child. Still be sure to get these calories from fresh whole foods, and stay away from irritating, acidic foods like cabbages, onions, and citrus, which can make your baby not feel as good. 

Great questions!