Mine do. I don't like the baggy saggy feeling of slowly losing my pants, especially on low-rise jeans. Not far to fall, you know. So I added an extra button about an inch to the side of the real button, just to take up some slack when they stretch. I think the extra button looks fine, and when it is in use you can't tell it's an extra. It doesn't pucker the front or anything. I wish the button were a bit bigger to match the original, but I don't wear a lot of stuff tucked in so it is not big issue.
buttoned at original button.
buttoned at my new Sag-B-Gone button.
This is what I used and they couldn't be easier to attach. "Dungaree Buttons" from my local Wal-Mart. You just put the tack through the back of the waistband and push on the button from the front. No hammer or man-handling required. Be sure not to put it too far away from the original button. You don't want to create an unsightly pucker. Also be sure it's in the right place before you attach it! It's a lot harder to take off than it is to put on.