I think therapist might be hard to offend, and even if you did they can't really tell you that can they. They should have done lots of work on themselves to get to this point so I'm sure you can talk freely about it.

We might have said loads of things that offend them and would never know...stuff about people, places, politics, family ..we just can't see those things so have no idea if they go against who the therapist is.

So I would just tell them exactly how you feel about your weight issues, if they are upset about it then that's something they need to work through with their own therapist.