I went from a raw food vegan diet where I weighed 215 pounds to a red meat diet where I eventually got down to 160 pounds.
I currently weigh 180, and at 5'4" that may seem like a lot but I am a weight lifter (seriously, I bench 200 pounds now) and I also have a pretty good set of abs. My last body composition test had me at 19% body fat, which is pretty much ideal for a woman. Sure I'm an anomaly, but it's working fine for me.
I am actually very large boned for my height (40 inch rib cage, and you can actually see and count my ribs right now.)
So to answer the question of "Am I thin" it depends on what you see. People don't say I'm overweight but they don't say I'm thin either because I'm short and very stocky... built like a dwarf. But if you were to see me without my clothing on then you might say I'm a smidgin too thin.