It runs both ways flamenco.Personally, I think people are more sensitive about overweight issues than underweight issues and watch what they say. Look at the criticism Jill Franks and Anna gets. It is open season all year round.
I watch my weight to keep my weight up. My daughters are both lightweights as was my mother. We are all short too, my youngest being lanky at 5 foot. That's us. My father's side has quite a few heavyweights.
When ASDA introduced a size 4 into their range a few years back my youngest daughter was delighted. The flack in the press was astonishing.
But,there we are, that's people for you - a mixed bag of all shades of opinions and preferences. Everyone is entitled to their opinion and as I say to my two - do you really care what random strangers or acquaintances think?
The answer is "No." The only opinions that matter are the ones that are expressed by people we love,know and respect.