Physical contact and a favourite lullaby did it for us. We started with a baby carrier and advanced to just putting a hand on the baby while they were lying in their bed. The noise of the door latch would wake them up, so we kept the door open for a while until they were fast asleep. It was a lot of trial and error, though.

Of course! That’s what tracksuits are for…

There are kids with tracking?

BMI is generally a shitty indicator. I had 16 at some (rather long) point in my life, and now, I… let’s say, don’t. If his blood tests are fine and he’s functioning well, I’d let nature run its course, especially if he’s eating well. Pushing empty calories into him is just going to create food intake disorders.

—a person who’s been in somewhat a similar situation and who’s around several people with food intake disorders and a father to a very skinny kid presumably without one

That’s bold of you to assume their emotional needs aren’t being met. Either you’re a parent whose basic checklist doesn’t include giving the kid a cuddle, or you’re not a parent, in which case rest assured that most parents’ checklists do contain cuddling their babies when they’re crying.