When I was studying at U Penn supposedly toward a Liberal Arts degree, I ran into one Education professor who almost become hysterical when I told her that fat people constituted an oppressed group. I would bet anything that all or almost all of the professors who led poetry workshops I attended (Brandeis U. and Boston U.) would have felt the same way.
Thus it was all the more liberating for me to be able to write about how it is to be fat in this thin-centric society of ours and to have your voice dulled or muted because you can't write in your own skin as a fat person. Or - you couldn't, until recently. You had to pretend that you were writing as another slim person, or put another way, someone who was sufficiently like everyone else who didn't think about being different. Someone who was part of the great mass of non-bodied, unembodied poets.
This was not only because a lot of poets disliked the mention of deviant bodies, but also because they had been sufficiently inculcated with the Puritan attitude toward bodies in general and found their mention embarrassing. How doubly embarrassing for them then, to possess a "loud" body and not to be embarrassed about it.
This is why, until recently, you did not see many poems written by fat poets about being fat.