For weight, I typically just say "thin," "average," or "heavyset," I never try to specify a number.
I don't find this "backward" at all. If it's a big restaurant and the server's name is Avraham, DeShawn, Muhammed, or Conner, ethnicity might not be needed to identify him. But what if his name is Michael, David, or Joshua -- and there are four of each working there?
It's a description, not a judgement. Same as reporting on whether someone appears to have blonde, brown, red or black hair. Ditto for weight -- "She weighed a whopping 400#" is offensive. "Weight: 225#" is not. They're simply descriptors (except for the one example.) Walk away from the PC madness.
[fyi, the names in the second sentence are from a baby site which lists most popular names for different ethnicities. Michael, David, and Joshua apparently cross most all ethnic borders.]