I knew I shouldn't have opened this thread but curiosity got the better of me and now I'm regretting it.
OP, being thin shouldn't always be aspired to, you're correct. I had a BMI of 18 until I started medication which caused my appetite to disappear - my BMI is now 16.3 and I am trying my best to build my weight but it is not a fast process.
I'm only in my 20s but have always been called a "twig", "stick", "bag of bones" etc before my weight dropped by strangers so it's nice to see that I have a future of being refered to as "haggard", as well as other descriptors I wish I hadn't read. I won't be returning to this thread as it's obviously not good for anyone to have to read what people secretly think about those of us who are very thin, whether or not we can help it. Ignoring all of the unfortunate comments, I would just make this one point to OP's original post:
OP (and to the rest of the posters), be whatever weight you feel most comfortable with yourself at and that means something different for everyone. But also please try and consider that not all "thin" people are happy in the way they look and nor are they all healthy just because they're thin, so you should never feel pressured to look thin, or to look any certain way for that fact. You should just want to be happy and that has a different definition for everyone. Whether or not being thin is the current "beauty standard", it shouldn't be relevant if it isn't your beauty standard. Beauty is in the eye of the beholder and you should aspire to be however you feel happiest with yourself, most comfortable, most healthy. Being thin does not always equate to being healthy. If you can get all your vitamins, stay hydrated, eat a fairly balanced diet, get some decent sleep and some exercise if possible, you're on the right path to health regardless of your size.
No one on either end of the spectrum should be made to feel ashamed of their weight or size. I'm bowing out of this thread now and will take more care in future not to venture into threads like this.