I wouldn't ever mock anyone doing exercise whatever their size, and realising that it takes much more effort both physically and mentally to do so.
I go to the gym in winter, often I'll watch the staff showing a fat person around, especially in the New Year. Often they do not join because they are intimidated by other gym users who they believe to be mocking them. The opposite is true! We all know walking through the door is the first and hardest step.

How the bloody hell they can do this i don't know but off i went to the doctors for a rant,fighting my way past all the obese, health service money absorbents to have it out. I had a rant about the number of fatties and how much they cost then i was told that the prescription would be started again. Sometimes you've got to make a stand!