Having been a reader of fat-acceptance writers like Kate Harding for a long time, I can safely say that there are many people/commenters who are deeply concerned that if we don't shame and insult fat people for their weight, they won't be motivated to lose it. This "idea" was just dealt a major blow by researchers from the Florida State University College of Medicine, who that found that shaming fat people about their weight correlates to weight gain, not loss:
Participants who experienced weight discrimination were about 2.5 times more likely be obese by the follow-up survey and participants who were obese in 2006 were three times more likely to still be so in 2010, the researchers wrote.
This is no tiddlywinks study, either. Researchers followed more than 6,000 participants for four years, and their findings suggest that stress and shame contribute to binge-eating. As many fat activists have long pointed out, making a spectacle out of someone's body tends to discourage that person from using it in ways that draw even more attention. Working out or even just taking a walk is hard to do if everyone around you has a comment to share about your body. And that's when you're even allowed to exercise. In some cases, as with the Boy Scout Jamboree, fat people are openly excluded from exercise, despite all the exhortations aimed at them to get more of it.
The debate over the fat acceptance movement often gets lost in the weeds of debating whether obesity is the cause of problems like heart disease and diabetes, or if it's just a correlation and therefore it's perfectly possible to be a fit fat person. But whether it is objectively unhealthy to be fat, shaming people over being fat is a bad idea no matter how you look at it. All shaming someone gets you is a person who feels bad and is probably making even more unhealthy choices because of it. Regardless of where science falls on the subject of "is fat bad for you?" we know that shame absolutely is.