RE: When, if at all, did you start your baby on cereal?
Monique...
Rachel and some of the other mamas probably know more and I'm nursing a sleeping baby right now and don't have two arms to search much, but I wanted to add that breastmilk is way more calorie dense than solids particularly because it is so fatty. Which is why studies have indicated starting solids does not actually help the baby sleep better.
Personally, I'd tell my ped that I'd prefer to stick with the AAP recommendation to wait until your baby is 6 months and that's why you didn't start solids sooner. It would be tough for him to argue with that, and if he does, I'd tell him/her to do some reading and get updated on the new recommendations.
I'm sure someone else will know more but I wanted to chime in that breastmilk is plenty calorie rich and solids aren't likely to make your baby gain any faster.
Mama to DS-2004
DD-2006
and a new addition-ds born march 2010