Re: Need info/studies or overreacting?
16-18 oz over 11-13 hours sounds reasonable, and that amount does not need to increase like formula fed babies. I am wondering what time frame your pediatrician was looking at? In the beginning few weeks both FF and BF babies will increase volume, but in the big picture they do not follow the same pattern. My son drank 14-15 oz over 11ish hours everyday starting at 3 months old and is healthy and average size in every way. (We are down to 12 oz now due to eating more solids but never went over 15 oz).
As for how often he has a bottle, that depends on how your baby likes to eat. When you are nursing him is he a snacker, as in short and frequent nursing session? My son was NOT a snacker and liked to nurse a bunch at once then wait 3-4 hours, so he had 3 larger bottles, rather than 4 smaller bottles at daycare.
My little man was born 12/17/2010.
Baby girl was born 4/30/2014.