I think it's easier to 'return' to being skinny, because that person's body already knows how to be skinny.
I've been the fattest kid on the block since I was able to walk.* My body really didn't know what being is like.* I'm still not thin, but I'm not really that heavy anymore either.

The point is, my body had to learn how to 'not be fat'.

I could be wrong (since I've never really been thin) but I would think that if you were thin before (especially if you recently thin and not thin as a child, say 30 years ago), then it might be easier

Sorry, something weird happened.* I posted to several different threads, but the responses all ended up in this thread.* Very strange