The key word is maintanance. If you go through all the stages of the diet adn not try to do induction the full way, you should of learned healthy eating habits by the time you've reached maintanance. That is why OWL and premaintanance are so important. You learn what your body can and can't handle.

It's not just about number of carbs either. For some people certain foods act as triggers for cravings, or cause weight gain and bloat. It also teaches you to tell the difference between water weight and real weight.

If you go back to eating mostly carbs, transfats, and junk food you would gain weight back no matter how you lost it. Stickign with whole foods such as plenty of veggies, fresh meats, fruits, fresh dairy (as long as you aren't sensative to dairy) then maintaining shouldn't be to much of a problem. I'd say still check your weight once a week or once a month. If you have gained a little, then eat a bit lower carb or cal for a bit to shed it again.

If you don't let yourself get out of control and you watch eating habits and weight, then maintaining should be alot easier then losing. For many though it can be the hardest part. Not only from getting lax, but deciding to go back to old ways of eating, not exercising as much, or not being as motivated when you no longer are striving for a goal and seeing reults to that goal.