PPF, your 6'3", and you want to be 160 ? That sounds REALLY thin to me. Even with a thin build, I would think 190 to 200 lbs would be much healthier.
I'm 6ft, and I want to be 215 (with less than 10% body fat, of course).
But hey, about skin sag....
After losing 75 lbs in the last 9 months, that's certainly a subject of great concern to me. My stomach and sides are definitely saggy, and loose, but not so much so that their are any folds. I've heard it said a few X's, and I have to agree, that often when people grabs their sides and bellies, and say, "See, I still have all of this loose skin....." A lot of what they are calling loose skin is the last remaining amounts of fat, which is making that loose skin sag even more.
Anyway, I've also read that if one loses a lot of weight fast (the example was 60 lbs in 6 months) that one should give themselves anywhere from 12 to 18 months, to regain maximum skin tightness. It went on to say, that most reputable surgeons would not even consider plastic surgery before this amount of time had passed, knowing that things might still change on their own.
I try not to let myself worry about this. Certainly no excuse to not lose the rest (or most of) my fat. If in 3 years, I'm in the most outstanding shape.... but still have some really loose, bothersome skin, then I might consider surgery, but I'm confident I won't need that.
Peace,
Fish