I hate this stuff. Bullying someone for being fat is about as likely to make the obesity rate go down as calling people who wear glasses "four-eyes" is going to reduce the rates of astigmatism.
Yes the average weight in the west has gone up, and this isn't great, but more people being fat is a symptom, not a cause of higher rates of lifestyle diseases, and higher rates of lifestyle diseases have been caused by social changes over which fat people have no control, like the rise of the automobile and processed food.