Thanks HK. I have to agree with your points, particularly:
I also suspect that we've become (societally, I mean) conditioned to expect kids to be.... er... "plump."
LET. THEM. GET. HUNGRY. This was the hardest thing for DH and I to learn.
The book I linked to earlier, "My Child Won't Eat!", makes a similar argument about how we, as an affluent society, have distorted satiety awareness and risk imprinting it on our children through loving coercion.
In our family, we're fortunate to have seen two paediatricians, one with a feeding specialist on staff, both of whom have ZERO problem with DS being < 1%ile weight for height. He's always tracked > 95%ile for height and > 75th%ile for head circumference but hasn't really filled out. I was somewhat reassured when I learned that my parents and I were similarly thin as children.
I still get antsy when I see my DS compared to his age peers. They are so...robust...and he looks like a wiry sprite by comparison, always running from experiment to experiment of his at Mach 2. But, when other children aren't around for comparison, DS never seems thin, just streamlined, YKWIM?
This thread reassures me that, maybe, our little professors just have a different set of needs than most children.