Why do we as a society still discriminate fat people from clothes?

I just saw a post on Instagram from the Instagram fashion account, with the title "why do we love fashion so much?". And within the post, they posted a picture of a woman (and I bet there's no fat women in there) and in the caption they said "We thank her for every moment she spends in front of the mirror and for every experience she has and tells us about. We love her because she justifies our presence within those moments and experiences. She is the center of our universe.".<br><br><br>And its true, we don't take fat people as people who also like to wear fashionable clothes. A lot of brand don't produce clothes in bigger sizes. Fashion brands don't have fat models so people can imagine themselves in the outfit because everyone looks different. But for me, I bet there's more people that are plus size than slim.<br><br>Why do people who are more fat, can't wear clothes that everyone else ? I just don't understand why, and it's sad.