I think Maria Kang got a bum deal. Once you get into gym and fitness culture, you'll find that someone's always hawking something. Her ad was targeted toward her niche followers and potential customers looking for motivation. When it went viral, many didn't bother with the context. They just said she was fat- shaming.
I try not to but I do believe people should take care of their bodies. If they are happy with they way they look though, I guess I have nothing to say. I was raised in a very shallow family so looks are everything. My mom used to tell me the day I was to get fat she'd disown me.
No. But I'm willing to give them advice if they want to learn to eat better. I used to be borderline fat so I know how it drains your self confidence and how hard it is to shed the weight off. It's almost as if you were giving up on drugs (sugar is a sort drug IMO).