My baby is formula fed and he was four weeks old yesterday. Lately he seems like he just wants to snack all the time. I typically offer him four ounces and he'll eat between 2 1/2 to 3 1/2 ounces every 2-3 hours.
The last few days, He'll eat an ounce or so, then take a break for 15-20 minutes, then want more. Feedings will be spread out over about an hour and a half or two hours and sometimes he'll end up with 5 or 6 ounces throughout the extended feeding. It's hard to know where one feeding stops and the next begins, other than when I make a fresh bottle.
He'll be upset and rooting, so I know he's actually hungry, but this snacking is throwing me and I worry that I'm over feeding (kid is a tank these days--he's out of newborn and filling out his 0-3 month clothes). Could he be having another growth spurt (3 week was pretty mild for us and happened a few days early)? Is there anything I should be doing to get feedings back on a more regular schedule? I try to bounce him or offer the pacifier, but he just wants food.
ETA: we did just switch from Gerber to Up and Up version of Similac Advance. I'm not sure whether that's related, although I think this may have started before the switch. I don't remember for sure which day it started.

Re: Snacking versus meals--bottle fed babies
This is us as well. I usually nurse him if he's still fussy before he falls back to sleep though. Or DH does a very small bottle.
Emma Kate - born 10.16.03 @ 29 weeks, weighed 1lb 13oz and 13.5" long.
TTC #3
BFP #1 - 07-15-12; Natural MC 07-18-12
BFP #2 - 09-29-12; U/S showed baby stopped growing @ 5wks 4days - 10-30-12; D&C - 10-31-12
BFP #3 - 04-10-13; Third time is a charm... Stick, baby, stick!!!
This is us as well. I usually nurse him if he's still fussy before he falls back to sleep though. Or DH does a very small bottle.
Same for us here.
CP: 01/2011 | MMC: 01/2012 | MMC: 10/2012 | DS: 11/2013 | MMC: 11/2014 | DD: 01/2016
BFP: 06/2018 - EDD: 02/09/2019