If you dress like a slut, frankly people are going to think that you are a slut!
This one I know from experience. I lost 30 pounds my freshman year of college (I know, I know I went backwards) and decided that to really celebrate I should show off my body, all the time. Let me tell you, the outfits I came up with were interesting to say the least. The skirts alone looked like headbands. And yeah, I had the body for it but believe me the reputation came along with it (and I may have embraced that as well for a period of time). So just remember that you are what you wear sometimes, whether you want to be or not.