Losing weight...

I wonder when riding a bike if losing 5 pounds of "bike weight" feels the same as losing 5 pounds of "people weight".  I know there are plenty of skinny riders but I also see heftier guys rolling around on the most expensive Specialized, Cannondale, and Pinarello bikes available.  Bikes where you have to be paying a huge premium to ride something so light under someone so heavy?  Maybe there are some physics calculations that show it's more impactful to lose bike weight that body weight.  I certainly hope so, it would be a great excuse for some Zipp 202s...