How to get my sister to stop?

she is 21 and i'm 16. i think she has low self esteem because she always points out the flaws in people, including me. i hate it. i don't think i have all those flaws, i know i'm not perfect but when it comes to physical flaws i don't pay too much attention to them because that will only make me nervous and uncomfortable with myself, which isn't going to help anything. I just do what i can to make them better and just ignore the rest. But she points out everything as a flaw. My large boobs, my big butt, my braces (which aren't my fault), she says that i look like i'm 12 (even though i've had many, many people think i'm older than 16 and tell me so) and she always says she is way more physically fit and "hotter" than me and that guys like her better. She says just because she weighs less than me that she has a better body, even though i am 7 inches taller than her and weigh 20 pounds more, and her body mass is a lot higher than mine, and people have even said that i have a better body than her. She doesn't take care of herself, she eats tons and tons of crap food, doesn't work out at the gym (though she recently started working out a little) and she really let herself go, where as I don't neccessarily watch everything i put in my mouth, but i don't eat much, i never over eat and i eat my fruits and veggies and try to limit my fat and sugar intake. I also work out for at least an hour, at least 3 times a week. I lost 15 plus pounds, and people always tell me that they can really tell and that I look amazing. My sister has gained a lot of weight. She once said to me "I don't like to brag, but I get a lot of attention from men....." in this stuck up, snooty voice that made me want to slap her. And when I said that I get pretty good attention from guys too, they notice me and check me out, she laughed. She has said that I am too young for guys to like me. Even with guys I like I'll be like "I think he was checking me out! Yes!" and she'll be like " no he was looking at me, the hotter sister for sure." and if she was just joking i wouldn't care but she is serious. Once she called me a spoiled whore for no reason at all. Just out of the blue. I'm not, I don't always get what i want and i've never even dated a guy let alone have sex with one and I don't even dress like a whore. She on the other hand wears tight and revealing clothes sometimes and she's only had one boyfriend, who she started seriously making out with during the first week or two of their relationship. She said if they were still together today then they would've had sex a long time ago. They were dating last summer. Today we went to the mall and there was this hot guy in this store with who i'm guessing was his friend and his girlfriend. He was hot but you know I'm not gonna flirt or try to get his attention because he's with his GF for God's sake. She walks like right in front of him to get his attention and when i walk the other way she is all like "see you have to try to get his attention. Not run away like you" but i didn't even care yeah he was hot but i wasn't gonna throw myself out there like her. And then she was trashing his GF and was all "Oh he could do so much better. Like me. I mean she isn't even pretty" and i could tell by the way she was talking that she was insinuating that she was fat. But this girl wasn't ugly, she was pretty and she did have cankles but she wasn't fat at all. I personally think that she was more attractive than my sister, with a better body too. I mean yeah i've done the whole "he could do better, like me" thing before with guys i've liked and the guy i currently like of course i think he would be better off with me, but i don't trash his GF and say she is ugly and fat when she's clearly not! My sister just always does that, she tries to bring people down to raise herself up and it will never work but she will just keep trying to do it. Last summer she wore a bikini with EVERYTHING hanging out. I really don't care about how food people look in bikinis i mean it's the pool or the beach, not a modeling contest so who cares. But what bothers me is she had the audacity to bash other people's bodies that looked better than her in bikinis! I've called her out on her behavior before, saying things like "just because you're insecure doesn't mean you have to take shots at other people/me!" but she never listens and just gets sassy with me. How can I get her to shut her mouth and start treating me and other people right?