I don't really know how the numbers balance out since we didn't keep track much before DD (and still aren't great about it

) however I can tell you what changed the most.
Lost my income to stay home.
As a result of being home, the heating bills are higher and the grocery bills are higher.
However - we spend much less on going out to restaurants, movies, etc and take fewer vacations.
I have gotten much better at cooking from scratch (and like to!) so we don't get take out as much now - although I agree that for the first 3 months or so we had DD we got LOTS of take out and ate lots of convenience type foods (Amy's frozen pizza's and canned soups, for example).
I am also much better at shopping for food....I know what a 'good price' is for items we use all the time, so if I am able to I stock up then. I also try to hit the discount stores once every month or two to help with costs (like Grocery outlet and TJ's). I can spend more time on those things - and meal planning - now that I'm home and this helps save money.
I buy less for myself now, and most of DD's stuff is second hand (well, mine is too but still!) so I think that evens out pretty well.