This would be me. I weigh somewhere in the range of 110 (maybe a couple pounds more) and am 5'4, which puts my BMI under 19, I think. I wear a size 4, sometimes a 6, depending on the cut of the clothes. It's my high metabolism, which I inherited from my dad's side of the family. I have had plenty of people tell me I look like I don't eat, but obviously they've never been around me at mealtime :) Plus, chasing 3 kids is good exercise!
[ jealous sigh ] My husband is like this, too. The man who wrote The Zone diet says that we sturdier people have been on the planet longer and we're type O blood.
I think he's right. Hubs is 5'9" and barely weighs 130, and is A+. Are you a blood type other than 0?
Everybody's blaming Twiggy, but I remember Twiggy (I'm really dating myself here,) and she was never anything more than a brief fad. Most people I knew, male and female, did not find Twiggy attractive at all. I was naturally underweight at the time, so I was glad to see Twiggy come along because at last there was a model who was thin and flat-chested. (Prior to that, the ideal look was more va-va-va-voom voluptuous.) It was a small comfort, though, because like I said, Twiggy didn't last long and few people really thought she looked good or tried to emulate her.