I just checked, and it turns out I have a mass of 413 lbs. Thankfully I also happen to be shaped like a perfect cube with a side length of about 12 ft 5 in, so I displace roughly 1920 cubic feet of air.
I leave it as an exercise for the reader to determine what my scale registered.
Yes, this does mean I am about 0.345% as dense as you are. I think it may be all the methane.
On a happy note, I seem to have about doubled my aerobic capacity over the last 6 weeks.
On a sad note, it looks like I am going to have to double or triple my (admittedly light) workout routine if I am ever going to reduce my side length to 11 ft 5 in and thus hit my goal weight. Either that or (shudder) diet.