That last sentence "USA fat people are overall uninterested in being thin" is pretty tone deaf. I would say that they are fundamentally failing to achieve their goal. Many have given up since they've tried (however unsuccessfully) since they were teenager with no significant results. Note that I have known several very overweight doctors so it's not just a "those fat people are ignorant about what to do". Losing weight is not as easy as deciding to lose weight, and the evidence of that is how few people manage to maintain their weight loss.
Treating this as anything other than a public health issue, rather than a personal failing is ridiculous.
It's very easy to lose weight. It's physically one of the easiest things you can possibly do, because you just have to not eat as much. Mentally it is hard, sure. But if you fail to do something because of weak mental, that is a personal failing. If you fail to quit smoking after years of trying, that is also a personal failing. Who else's failing would it be? You can shrug and say you're just going to remain fat because it's a public health issue, but while you do that, other people are eating less and losing weight.
> other people are eating less and losing weight.
No, they're not, and that's my point.
Look at smoking that you mention. Smoking was unbelievably common a few decades ago. It's now pretty uncommon (in North America). Why? Were people just failing in the past, and now aren't failing? No, we made public health decisions that have dramatically dropped the proportion of the population that smokes cigarettes.
IOW: Treating it as an individual failing may feel good, and may even be "true", but it's not a useful framing of the problem. Treating it like a public health issue is massively more likely to work than just wagging your finger at people and telling them to just eat less.
Yes, when dealing with populations, enacting laws and propaganda that affects whole populations is the most effective way to change them. As a population, to fix fatness we need to do big things. But as a person, to fix fatness you need to do it yourself. If a doctor says you need to lose weight and you don't, you failed yourself. The system could have helped you, and maybe should have, but ultimately you failed.
To my initial point, Americans are overall uninterested in becoming thin. Public policy may be able to change that. I don't believe that people generally wanted to quit smoking in the 50s but couldn't, but instead that they generally didn't care about quitting. The same is true now for being fat. Only once the public consciousness shifted toward smoking being bad did smoking rates fall. That was a consequence of desires shifting due to (benevolent) propaganda. I'd love if we had similar ads on TV and such for fatness like we did for smoker's lungs.
Treating this as anything other than a public health issue, rather than a personal failing is ridiculous.