You should not decide someone's value or worth based on their appearances. Whether women are fat, or chatty, or "slutty", has nothing to do with you--and moreover, fat is not a bad character trait, chatty is not a bad character trait, and "slutty" is not a bad character trait.
I am sick of women being forced into these small parameters to please other people (but men, mostly), because we are people and we live for ourselves. If we want your opinion of us, we will ask.
If a woman is fat and she's happy, that's great. If a woman is skinny and she's happy, that's great. If a woman likes to talk, think about a man who talks as much as her and ask yourself if you're going to find him annoying and an earful. If a woman is sleeping with several people and she is happy, that's great. Men who sleep with several woman? Wow, what a charming lad, he must be desired for a reason. How dare women be attractive to other people and let said people touch her!
I hate words like slut, whore, trashy, and anything else along those lines, because it implies that when a woman does the same things as a man, she is shamed for it.
Conversely: If a man is fat and he's happy, that's great. If a man is interested in astrophysics and wears thick-rimmed glasses from reading books all day and expanding his knowledge about what interests him and makes him happy, that's great. If a man doesn't bench press or is athletic with muscles and physical strength and he's happy, that's great.
The point? Feminine traits, regardless of in a man or a woman, does not measure an individual's worth. Nobody lives to please you, everybody lives to please themselves. Also, if this is how you judge whether or not you want to be associated with a person, s/he probably doesn't want to be associated with you, either.
As far as body image goes, I am a promoter of health. If you lead a healthy lifestyle, whether it's with your diet or with your exercise or with both, then I don't care if you're fat or skinny. Fat is not synonymous with ugly, nor is it synonymous with unhealthy. It is a descriptor for your appearance. If you are unhealthy, however, and I am not close with you and you did not ask for my opinion, I will not condone you, because it's your life. I will lead mine, and you will lead yours, and we will not force our intrusive opinions on each other.
How is it that we live in the twenty-first century and still find it so difficult to understand the concept that everyone has a right to happiness? If someone is not hurting people, then why on earth should you stomp them down for who they are?
Let people be fat. Let girls be promiscuous. Let boys be nerdy with noodle arms. Concentrate on yourself instead of someone else, because at the end of the day, the person who you're going to be left with will always be yourself.