I'm going to go out on a limb here and point out that physical sexiness (and health) can come in very different sizes for different people.
I lost 70+ lbs and have kept it off for five years now. Before I lost the weight, I had no shape--no waist, no butt, and relatively unendowed up top. I took immaculate care of myself, but there was no way my "figure" could have been considered feminine. I was "apple" shaped in the worst possible way. It was physically impossible for me look sexy in plus-sized clothes intended for curves.
The only way I could make up for it with personality was to be bubbly, self-deprecating, and unbeatably positive--then, very rarely, someone would express attraction to my personality. But that wasn't me. I'm intellectual and introverted; I like people but not as much as I like books; and I'm extremely proud of my achievements, so self-deprecating doesn't work for me. So, being attractive at that weight meant being someone I'm not.
Since I've lost the weight, many, many people have told me I'm quite attractive (not everyone, obviously, but that's fine). I am NOT curvy. My natural build is more boy-like: strong, square shoulders, narrower hips, a toned, tight backside, and a modest bosom. Occasionally, I'm made to feel like I'm unfeminine because I'm not curvy and don't have much extra meat, but eff 'em, this is my narrow, lean, "boyish" body and it looks better at a size 6 than it ever did or could at a 16.
I can't be what I'm not. Regardless of my weight, unless I pursue some massive plastic surgery, I'll never be curvy at any size. I hated how I looked when I was fat, and I love how I look now.
In this weight debate, I see a lot of hostility toward round, curvy pegs being forced into square, thin holes. But I'm the opposite: I'm a lean, square peg who was miserable trying to live in the round hole.
Possibly all anyone needs is a solid sense of self.