Size "Zero" is Invisible

Yes, I may have been eating like a pig during the Christmas holidays, but I have to say after watching many weight-control commercials that there is no such thing as a size zero. Who invented this sizing BS? If you are alive and existing in human form, you cannot be a size zero! It goes against the laws of physics. "I was a size eight and now I'm a size zero," claims a woman that I can still see on the TV screen. What?!!