There are some that consider the term obese to be derogatory.

I don't agree with that opinion, but I can understand where they come from. I generally support body positivity with a heavy dose of realism. Being overweight shouldn't be a reason for someone to treat you poorly, but pushing the idea that being overweight isn't unhealthy is where I draw the line.

If I were medically overweight I'm sure I would also not like any term that directly points to something considered a very negative trait, however clinical the word is.