A lot of what's considered attractive in women is consistent across cultures because it's based in biology. Almost all cultures value symmetry in face and body, clear skin, long thick hair, low body fat + good muscle tone, low hip to waist ratio, full breasts, etc. Because they are all indicative of some combination of a prolonged period of good health, high reproductive capability, and sexual maturity. This shit doesnt happen in a vacuum. There are deeper reasons that inform our aesthetic preferences for slim bodies.