Question

Obesity is not a protected class under Title VII. Based on federal law, is it OK for Linda to openly express concerns about her overweight coworker, Ed$?$

No$,$ Linda's conduct would still create a hostile work environment, regardless of the legal status of obesity as a protected class

Yes, illegal workplace harassment is limited to the federally protected classes

It depends on other pertinent factors, such as whether Linda speaks privately to Ed$,$ whether he welcomes her concerns, and, if not, whether Linda is persistent with her concerns even after he asks her to stop.