I didn't lose any hair. Most people do, but for the vast majority, they're the only ones who notice it.
as for saggy skin, yep - very common. Although if you ask most vets, they'll say that they'd take their saggy skin ANY DAY over being morbidly obese. In retrospect, I'm not sure why I wasted one brain cell worrying about it. i am SO much happier now that i'm normal weight!!! Plus, for most people, it's pretty easy to hide - you'll likely be the only one who knows it's there (other than your partner and doctor!)