Hi - congrats on the new wee little one!! I am a mom of 2 little guys - one is 2 months shy of his 3rd birthday and the youngest one just turned 9 months old. Both have been on the 0% or 1% on the growth charts for weight. Yes, you read that right - 0-1%. My oldest was often less than 0, but they don’t really track that… Both are healthy as can be. My favorite saying is that someone has to be the 0% that everyone else is judged against. Both were/are breastfed.
Best thing the docs and nurses at the clinic we go to said was this: As long as his growth curve is going up, and he’s not regressing in weight gain - he’s fine. Doesn’t matter if he’s in the 0% range or 99%. That really helped calm our fears.
With my oldest, we were freaked out for a long time - he’s not gaining weight very fast, he’s not getting enough milk, etc. At 5 months, we finally started to suppliment with formula. He gained one pound in about a week, then went right back to gaining just as slow as breastmilk only. By 10 months he had completely weaned himself as he preferred the bottle and I was spending way too much time pumping to only get 6 - 10 ounces a day, so at that time he was on formula only. When we started solids, he had a lot of avocado and egg yolks as they are high fat and a lot of full fat yogurt when he hit a year. He’s still a skinny dude (about 28 pounds soaking wet), but he’s taller than all the other kids his age and smart as a whip for not yet being 3.
My younest is pretty much on par with the older one as far as weight gain goes. I think his last appointment he was 1.74% for weight but 75% for length. He absolutely refuses to take a bottle though (we’ve tried more times than I can count), so no chance to supplement with him which I’m ok with as I really wanted to go a year with my oldest and supplementing definitely affected. We are chalking it up to genetics. My husband was the same when he was young, and my brother was too. My brothers kids are still lightweights and they are 6 and 8.
If he was lethargic, not peeing or pooping often enough, rooting all the time etc, that would cause me to worry, but your boy sounds a lot like mine. Feed on demand instead of on a schedule so he gets to eat whenever hungry.
As for you wife, take it easy on the exercise for now (like it sounds like she is doing) and make sure her supply is really well established. I still eat like a horse (probably more than 500 extra a day, but who’s counting?) to make sure I am producing enough milk as I don’t even want to come close to not producing enough for him.
From a mom who has 2 kids who never had a single fat roll - I totally understand your post! Hang in there, don’t stress too much, and don’t let the doctors freak you out! Talk to them about the curve of his growth chart, not just the numbers. Don’t jump right into supplementing if there are other things you and your doctor want to try first - as it can have a negative impact on nursing. Some babies take to formula and nursing without any problems at all and some don’t.
This is what we have experienced. Hopefully others will chime in. If you have any questions, let me know! And again - congrats!