BTW - I have been giving a lot of thought to SebC's "smoking" vs "obesity" comparison. It is true. We shamed smokers. I was part of that. "You smoke? Really? That's disgusting." Thinking back on it now, I feel pretty ashamed of myself for doing that. I don't think being cruel to people is the right tact even if I was doing it because I thought it would help their health.
BUT - and I say this without having ever attended a narcotics anonymous meeting - I don't know how many people tie up their self worth with their smoking the way that obese people tie their self worth up with their weight. Many people in OA speak about feeling worthless and depressed. And that's not a good place to be in.
This article below points out that people who are ashamed of themselves due to their weight are more likely to cope with these feelings BY EATING. While that sounds counter-intuitive, I know that's what I did for two decades. Bullying and shaming does NOT work. It's just being cruel to another human being. It was wrong with smoking. It's wrong here.
http://www.bbc.com/news/magazine-25749218