My son ate like a pig, when he was born... he was breast fed and had to be changed to bottle, becuase he ate like a pig. He would completly empty both breasts and then eat a 1-2 10-12 oz bottles at one feeding. Then by the time he was like 9 weeks old we had to add baby cereal to his formula to fill him up. MY friend had a baby the same way, along with her sister. They were all boys. None of them had reflux. They just ate like pigs. LOL My son was 7lbs 12 oz at birth and by the time he was 2 months old he was just about 15 pounds. He was huge. He still is and still eats like a pig.. he is 8 now.
I agree - sounds like comfort eating. Breastfed babies normally eat every 2-3 hours. My son was eating every 30-45 mins. He had reflux. Try pulling him away from the breast right before he is done and putting the pacifier in. That is how I got my son to finally take it.
have him checked for reflux---even if he doesnt spit up--he might be comfort eating, it usually peeks around 6 weeks. if you go to infantreflux.org, you can read all about it and see if he fits, and if he does, as long as you faithfully follow all the tricks, medicine is not required.