Ok, I'll try not to ramble here....
Matthew's 2 weeks old. Since he came home from the hospital, he's slept 6 hours each night.
He was nursing something like this (this is VERY approximate)... 11pm, 5:00, 8:30, 11:30, 1:30, 3:30, 6:30, 7:30, 8:30, 9:30, 10:30ish and all over again. As you can see, at night he seems to get hungrier than what I can provide. The doctor said after 20 minutes on each side, I can go ahead and supplement with formula. I haven't supplemented since he was a couple days old because I'd really like to get this regulated and exclusively breastfeed, although I'm not completely opposed to supplementing.
When he nurses though, usually the most I can get him to do is 10 minutes on one breast. I've tried waking him up, changing him, using the wet cloth (yes I'm evil) and 10 minutes on one side is pretty much it.
On the off times I CAN get him to nurse longer, or nurse both sides, he usually winds up throwing up. It's more than just spit up-- but it's not projectile vomitting either-- I'd say he throws up a good 1 1/2 - 2 oz. To me that indicates he's overeating.
His weight gain is ok, but not wonderful. He gained 14 ounces in 10 days.
So I guess my question is... what would you do from here? I don't want him "snacking" all day long, but I also don't want him making himself sick either. I also don't want him getting dehydrated because I'm not supplementing. Do you think it's possible that 10 minutes on one side is enough for one feeding? He's a big boy-- 10 pounds!
Ok, what do you think?

Are you getting at least 8 wet diapers a day? I'm guessing you are, which means he's getting plenty and isn't dehydrated. Babies can be quite efficient, so 10 minutes a side could be fine. I wouldn't supplement based on what you're seeing. It looks like he's getting enough to eat and eating often at night to prepare to sleep 6 hours.

I don't understand why doctors encourage supplementation so readily
 

To be clear... he's nursing 10 mins on one side only per feeding. Like he might nurse 10 minutes on the left breast at 2pm and 10 mins on the right at 4.

okay - this is my take on it.

in the evenings - babies tend to have 'fussy' periods. In the beginning when the mom/baby are figuring out cues and that sort of thing... its VERY easy to mistake a fussy cry for a hungry cry.

I would suspect. Okay, not even suspect, but KNOW that he's not hungry if he's upchucking all the milk like he is when you try to feed him longer. he's not hungry. He's full. And he's either confused at his gassiness and thinking he's hungry (which is very common too) but he's not... and or he's just maxed out on the stimulation for the day and is just fussy.

Andrew got super full after only 5 minutes of nursing. If I fed him any more than 5 minutes, he would upchuck what looked like gallons. BUT, 5 minutes was NOT enough sucking time for him. He needed to suck (as most babies do) so I had to use a pacifier for him to be satisfied. I was super efficient at nursing, he was super efficient too. Together, we only needed 5 minute nursing sessions. The Drs were fine with it because clearly, my gargantuan boy was NOT suffering from not enough milk.

Sarah - she had colic. And from 6pm until midnight, it was crying and screaming unconsolably. I could nurse her... but that wasn't what she really wanted or needed either. It was just plain old colic and a bad case of it too.
 

I think that he's getting enough, Katelyn does the same sorta thing, very rarely will we do both sides in one feeding.