There has been mention of this issue a couple of times - excess skin after weight loss. So I've done a bit of hunting about.
It seemingly works something like this:
Firstly, excess skin is probably not going to be a problem if you're talking weight loss of less than about 100lb / 45Kg / 7 stone or so. That's a pretty major weight loss that you would probably schedule over almost a year.
It's less likely to be a problem if you followed the advice to NOT lose weight TOO quickly!
It's also less likely to be a problem if you're younger (as younger skin is usually more elastic).
However, the nub of it appears to be:
1) keep the skin as elastic as possible with good nutrition (including lean protein to help form collagen and elastin) and good hydration. With all your 'new' eating habits you'll probably be avoiding junk food, eating lots of fruit and veg and fish and things - so that shouldn't be too hard.
2) avoid things that reduce skin elasticity / dry your skin out, e.g. excessive sun, smoking, sulphates / harsh soap, chlorine (so shower off after swimming)
3) keep exercising, especially weight training / muscle building stuff.
4) and skin-firming cream or collagen creams may help
5) there's also a miscellany of things like mineral/salt scrubs, massage therapy, seaweed wraps, yoga, calisthenics and rubbing castor oil over your skin that are suggested by various web-sites. (And a few more rather daft things which I've not bothered to list!)
How easy it is to deal with and whether someone ends up with a problem with it after weight loss really depends of their skin-type and how good a condition it's in.
But if anyone is interested in finding out more, there is plenty of advice around on the web, just search for something like 'excess skin after weight loss'. You'll have to judge for yourself what is good advice and what is nonsense.
There are, for extreme cases, surgical solutions, but these are serious surgical procedures with associated risks and should probably not to be entered into lightly.