I don't have any experience of belly rings, but I have noticed that my feet have become significantly smaller since losing weight (approximately 50lbs). There are some shoes that I owned at my heavier weight that I'm now unable to wear - they literally flap off my feet if I try to walk in them!
It isn't the length that has changed, but the width. I used to have to buy shoes that were a bigger size (and thus slightly too long for me) because the correct length shoe was too narrow. The change in shoe size makes sense to me - when I had a greater amount of weight pressing down on my feet, they spread out more and were thus wider. Since losing weight, there's less pressing on them, and less need for them to spread! That's just my theory, though. Or, it could be that when I was heavier, walking put a greater stress on my feet and therefore, more blood ran to them and made them more engorged. Who knows what it is, but I like not having such wide feet!