Why are women in general so insecure about their bodies?

Look don't get me wrong, I think all women are absolutely stunning but there's just something about big boned and curvy women that gets me differently. Since I was a teenager, I've always been attracted to the curvy girls and this girl turned me down when I asked her to the prom because the popular girls made fun of her and told her that I felt sorry for her and that's why I asked 😒