As one of those heavier women, though I'm not on any dating sites, just no.
BBW doesn't stand for "big, beautiful woman", it stands for "I let myself go, have self esteem and self worth issues, and don't feel badly enough about it to get myself in shape". It could also imply that they're over 200lbs, 300lbs, 400lbs. Thank goodness for the label "SSBBW", though, to make that distinction right? Wrong.
We KNOW we're fat. Some of us care enough to do something about it (See: r/loseit, r/progress pics, r/Keto and so on), and some of us don't (see: r/Dying to beat and any sub like it). There are obvious middlegrounds, but when it comes down to it, we don't care about our weight, so why would a man want one of us? That can't be healthy thinking on his part either, whether he likes it or not, something is mentally off about the choice of wanting to be with someone who's "BBW".
Obesity isn't beautiful, obesity is dangerous, and society can't make up its mind if it agrees or disagrees because they don't want to be rude, and "offend" anyone. Obesity isn't something to be lauded, so that's why we hide it. I know I sure as fuck used to. I'd use MySpace Angles(tm), too. I'd use Photoshop, and dim lighting, oversize clothing and the right pose. I knew how to hide it, but sooner or later, you had to meet, and no diet in the world can save you from you.
I really, really hate people encouraging the Fat Acceptance movement, and the Healthy At Any Size movement, because it just isn't true. Even if you're 200lbs and healthy right now, if you stay 200lbs, or get heavier, it WILL catch up to you. I'd know. It caught up to me with Diabetes, PCOS (remember, obesity is an endocrine disruptor), arthritis, neuropathy, infertility, partial blindness, and assisted with my intense depression.
There's a reason why being fat is still unacceptable in society, and that's because we're walking ticking time bombs. How honestly FAIR is it to encourage some poor girl to "Be Proud of your curves! (They're rolls), and be yourself!" and maybe meet a man who could tolerate her obesity/like it enough to "see past it (They don't, Honey)" and love her anyway, only to have her gain health conditions later in life that are going to kill her?
He'll get maybe 10-20 years with his wife before she dies, or before she starts to decline in health, because she WILL decline in health before he does. She may or may not die before him, but she WILL get worse, provided she stays a "BBW". I don't think it's fair to either party.
And you men who "PREFER BBW's" should be ashamed of yourselves. You need higher standards than the walking amorphous dead, my friend. I know, I know, "Tess Holiday isn't amorphous", yeah, but she's a nasty person with a nasty personality. "It's just what I like, and I don't know why", no, you're desperate for sex and something societally attractive won't screw you. It is LOW and it is DEPRAVED to prey on women like "BBW's" (I'm sorry, I can't say it with a straight face).
You are ENCOURAGING her early death when you tell her you LIKE bigger women. You are ENCOURAGING misplaced self esteem in the minds of the depressed. You are ENCOURAGING every single disease, limb amputation, and serious hospitalization when you call healthy women "SKINNY BITCHES"! No, they're NOT skinny bitches, they're NORMAL, HEALTHY, and a WHOLE LOT more beautiful than YOU, because they CARED ENOUGH about their bodies to maintain them! Whether they have a shitty personality or not remains to be seen, but they're at least healthy and functional.
And DON'T TELL ME YOU HAVE A THYROID PROBLEM! I do, too, but guess what? I lost 50lbs last year. I gained it back, because I got depressed, but I lost it. And those folks who can eat, and eat and not gain weight? They will. Everyone is different. But, the laws of Thermodynamics don't change. Fat loss (weight loss) isn't hard. It's the depression, the shame, and the apathy that's hard... ESPECIALLY with MEN telling these girls, "HEY, GUESS WHAT? I LIKE BBW'S AND YOU'RE SO BEAUTIFUL AND PERFECT! FUCK SKINNY BITCHES! MEAT FOR MEAN, BONES FOR DOGS, AM I RIGHT?"
Meat isn't FAT. USE a DICTIONARY!
(This rant was inspired by the guy on Facebook who yells a lot in his own rants. If you're offended, I'm NOT sorry. If you wanna argue back, go for it, but I won't read it. Obesity is not healthy. I'm 320lbs at 5'6", I should know first-hand. So. Sorry not sorry.)