I love when the bra threads online always attract the women with crazy bra sizes that it seems you never normally see. Like most women (mild exaggeration) are a 32DD in these threads. Where are all these women in real life? Where's all the 40B's that I see at the mall lol.
Id never do such a thing, even though I'm a male and don't ware bras. I have bought the same Tommy Hilfiger boxer briefs from Amazon for years. I can't wear regular boxers or my thing falls out the side and bangs against my knee.
Assuming we really are rare considering all your "fat women in malls", I think it's a multi-factor explanation, boiling down to "selection bias". This forum is NOT a cross-section of average america.
1- It skews toward millenials oftentimes
2- It attracts people who optimize their lives. A lot of women wear the wrong bra size, but I bet many many MMM women have spent the time to realize, "ah! the mainstream is wrong here too. The woman at [department store/VS] didn't know what she was doing when she added 5" to my measured band size!". So more women here wear "weird sizes" because we wear the RIGHT sizes
3- Many MMM are healthy, or trying to get healthy, and that included lower bodyweight. Avoiding processed foods, biking, etc? Microcosm.
4- This thread is itself suffering selection bias I imagine. If someone is content with where she buys bras, and finds them easily, she is less likely to click in. If she is an "odd size" and has a hard time finding them affordably, perhaps she is more likely to read or contribute in the hopes other women have good tips for her.
Anyway, my thoughts on what is likely explaining all of us wearing 32DDs.