I'm not saying it isn't, just that knowing and understanding that it is a choice doesn't get us much further from square one. Obviously, reminding a person who feels helpless that it is their responsibility and their choice doesn't really help them get off their feet - what needs to happen is to shift their attention away from the negative emotion. You might accuse my idea as helping them shirk their responsibility, but from my experience self-efficacy is tops when it comes to building motivation and building action. Sure, some could call it self-deception (although I wouldn't say that), but for me this is one of the situations in which the consequences justify all the little white lies that might be said along the way, as well as refusing to address the issue in speech as one of "personal responsibility" until that person becomes emotionally able to embrace that idea - which involves a lot of confidence-building before any talk of "personal responsibility".
I'm not overweight myself, but someone very close to me is, and I've seen the effects of this kind of behaviour first-hand. My own mother is in a group that specializes with weight loss of this kind, but this she intends to get lap-band surgery to help correct it. However, the specialist she was talking about this with was more than rude to her. She has a very legitimate reason for her weight, and it was because when she was in the hospital in the months leading to my birth, the doctors gave her steroids to increase her weight. Those doctors even told her that she would gain weight because of the steroids. She maintained a healthy diet of salads and healthy foods - not pizza and cake and sugary foods that aren't good, all while she was in the hospital. She kept on the weight all these years and has been struggling to loose it. But this specialist said, basically, that it wasn't the steroids that made her gain weight, and that it was the food that she was shoving (Yes, that's what he actually said) in her mouth. And when she came home from that meeting, she was really hurt by it. Not to mention that she doesn't eat a lot of sugary or fatty foods because she's diabetic and having too much sugar could kill her.
So I can see some truth to this. If you're just going to be plain-out rude to people that are overweight instead of helping them along the way, then they're going to simply loose the motivation to go on to loose the weight. They need that person that will give that kick in the butt, but not do it in a rude fashion. Because if all a person is going to do is brow-beat you, why even bother continue on with it if backtalk all you're going to get? It's not constructive or helpful in the least.
As I stated, I'm pretty much average for my age and height, hence not being overweight, but seeing this behaviour on people close to me has made me see just how it affects them. If people knew how to be patient when assisting people, it might actually work for more people. But some people just don't realize that weight doesn't magically come off overnight. It takes time, persistence, patience, kindness, and effort to get this to happen.
The entire yoke of my mother's side of the family is overweight or obese, my sister was obese as a child at one point, and I was overweight at one point as well – so I've dealt with this kind of stuff.
Being overweight or obese causes a lot of psychological harm to the person that's overweight, simply because of lethargia and other self-esteem factors that come with it. In a sense, you tend to feel worse more often if you're overweight than if you're not.
So, this study is correct, but what's its point? Don't shame fat people? Maybe. I feel a lot better about myself and others when I lost my excess 40 pounds I was carrying in my gut, and I'd like to stay that way.
I don't think it should be that much of a surprise that negative emotion makes things worse. Yeah, it might work for some people, but that type of approach only works for certain people of a particular mindset, I think. Positive reinforcement would make it stick better.
I've always had a fast metabolism, played sports, etc, so I don't know what it would be like, though.
Basically, if someone who is overweight wishes to lose weight, they should do it of their own accord. Because they want to and not because someone tells them to. I'm pretty sure every overweight person is aware of health benefits of losing weight. That said, I don't really care if you're overweight as long as you're a nice person.