Most likely obvious to most people, but…
When women go to the gym in Brazil, they go to get “thick” (for lack of a better word). What matters here, as far as a woman’s body image, are big thighs and a big butt. Skinny women are sometimes thought to be “feeling sick”, as in, “she must be losing weight because she’s ill”.
Women pretty much only go to the gym in the US in order to get skinny or keep their skinny body.
Fellow blogger Rachel’s view on the same subject.