Hi Sczoo!
Now, I'm a classic case of what you don't wanna do.

Although in my defence, it's taken several years for the weight to creep back on again and I'm still not as heavy as I was originally.
Scoot on over to the Cambridge Diary forum and check out Gretagrip's diary then Kira's diary. Both of them are now playing and winning the maintenance game and it makes for fascinating reading.
For what it's worth, I think it's great that you're thinking about this now. Whatever you decide, it needs to be something you can sustain, enjoy doing, and has enough leeway in it for you to enjoy high days and holidays without doing too much damage.