Do we have evidence that people who maintain a healthy weight do so primarily because of social pressure? I'm genuinely asking because I don't actually know that that's true. Most of the people I know of a healthy weight actually don't have a lot of shame about their bodies. In fact the most internal shamed people I know are either fat people or unhealthily thin people??

Anecdotally, I'd be way fatter if I was the last person on Earth. When all the Doritos were left, unattended.

Most people of healthy weight would feel shame about their bodies if they got obese. They maintain healthy weight partly to avoid that shame.

How do you know that "healthy people would feel shame if they got obese" -> "healthy people use shame as a motivator to maintain weight"? Doesn't that rely on the assumption that shame works?... but that's precisely the thing I'm questioning. I don't actually know shame works because I don't see evidence that healthy weighted people have more shame, are more sensitive to shame, or are shamed more often than fat people. If anything fat people have the most shame, are the most sensitive to being shamed, and are publicly shamed more often... and they're still fat.

30 years ago you would have gotten shamed if you gained a few pounds, that early signal makes people think about eating habits earlier and makes many people never go into unhealthy weight in the first place.

So even though shame might not work to get fat people to lose weight, it could still work to keep people from ever getting fat. Getting shamed for a few pounds means that you can fix the source of shame by dieting for a few weeks, very doable for average people.

Where is the evidence that shame has a causational relationship with people getting fat? You're still only pointing to correlation and saying that because shaming was more common in the past, shaming is effective now. This implies that healthy weight people respond to shame more strongly than fat people or something, but that's just not true in my experience.

This comment made me remember all of the anti-gay-marriage politicians saying that if we legalized gay marriage, men would just start leaving their wives and marrying men. As if the only thing keeping me from being fat or gay is some brave gatekeeper, rather than a lack of a desire (or makeup) to be fat or gay.

They also gave us insight into the mind of the gay anti-gay politician.

The difference is that the obesity doomsday predictions has already came true, and things are still getting worse every year. Today the median American is close to obese, and in some years will be obese unless something drastically changes. That would have been unthinkable 30 years ago when obesity was a tiny minority.