The fastening system is snaps on the front and under apron and a piece of velcro at the waist, so there really isn't a lot of room to grow or fade in them. I have lost a bit of weight since I bought mine and have been able to move over the velcro a bit. I also wear it a little higher than when I bought it to make it fit better and pull the belt a little tighter. If you are looking to drop a one waist size you could be ok, a couple of sizes would be difficult to adjust. I love my AK it's comfortable as hell and so far pretty durable.