I agree with everything you've said in this post but can I just ask, why is "weight chat" bullying? Grace is overweight. It's very clear. No one is laughing at her or sneering at her because she's overweight. People talk about her weight because they're pissed off seeing her photoshop her images and present herself as something other than what she is. And they're pissed off with witnessing naiive people think she is an amazing advocate for health because of what they see on the grid.
Let's call a spade a spade. Grace is overweight. She eats terribly, utter rubbish for the most part. She sits on her hole all day. She does no exercise and she looks so very unhealthy.
I don't see any difference between how Grace's weight is mentioned (for the most part) and how she's slagged off for being dirty. As she in her new zen state would say: it's what you put put to the universe. And that's what she's putting out there. She's a sloth.