The sad thing about every initial positive movement is that the lunatic fringe take over, shout the loudest and make everyone look bad. I myself have wrote articles explaining my problems with the body positivity movement, even thoug I credit it for helping me restore my self-esteem and improve my mental health.
I have stopped following BoPo hashtags and have full embraced body liberation, which sounds like what you are describing. My philosophy is…people should have total autonomy over their bodies, what they do with it is their business. I will passionately defend this. If a person chooses to stay fat they should be able to live their lives without judgement, hate or prejudice being thrown at them from every direction. Finally, if we could all subscribe to the maxim “if you haven’t got something nice to say, don’t say anything at all” the world would be a better place.