To make a kilt smaller, you either move the buckle(s) on the apron edge and move the underapron strap, or you take in the apron and underapron on _both_ edges (a big job).

Even if you're absolutely sure that you won't gain the weight back, I'd wait to buy an expensive trad kilt until you lost about half the weight you think you're going to lose. That way, if you gain a little back, the kilt will still look good. It's easy to move the buckles a couple inches and still have no one the wiser that the apron comes a little too far over the pleats.

There are lots of threads on the forum about how to move buckles.

B