How skinny do you have to be to get your belly button pierced?

Who has a navel that is acceptable for piercing? Well ultimately the best bet is to see your local professional body piercer, they can look at your navel and tell you if it's going to be an issue or not. Excessive weight can cause the tissue to be misplaced due to tissue rolling, this will make placing the piercing in the right place a real problem. But without seeing what you have to work with it is really hard to guild you down the right path. So see your local professional body piercer for assistance.