My dd was 2.5kg and she fed 3 hourly max around the clock until about 4-5 months. The maternal health nurse and paediatrician were horrified that she was feeding sometimes 10 times a day at that age! Mainly for my rest and sanity so we cut it down to the 6 or so recommended feeds per day at 6 months and she actually started eating and sleeping better so I think the amount of feeding was mainly just for comfort rather than food. She has followed the 25th percentile curve since her due date (born at 36 weeks) so has just never been a big child. Not sure this is what you're after but just my experience with a small baby.