I know most of you will probably think i'm crazy, but having spend years trying to get bigger, i really can see this from a thin persons' point of view.
I'm 5'4" and weight 44kg, and my bmi is around 16.7, the most i have ever weighed was about 48kg, the only way i got bigger was by doing lots of weights at the gym, and eating loads of protein (i also drank Guiness every night).
I've always tried to eat a healthy diet, because being thin doesn't mean you're healthy... a lot of people seem to forget that, and accusations of eating disorders then follow, just because you want to put on healthy weight (muslce), and not just fat.
Getting trousers that fit can be a nightmare, my legs aren't short, but being a small size 6 (uk), means i can only find trousers/jeans in 3 shops that fit me (and that's if they happen to have the right styles in etc).
I feel self conscous being at the gym, because i don't want people thinking i'm trying to loose weight, and i've given up swimming all together because of my shape.
Just a few examples of how being thin can be a right pain in the neck
Thanks for those who have posted similar, it's good to know not everyone that thinks about weight is trying to loose it