I don't understand why we're acting like preventing obesity for society at large is an unsolved problem. Looking at Japan with an obesity rate of 3%, it's clearly possible.
Whatever Japan's strategy is, I can guarantee it is not the type of lifestyle that is convenient in the US, and it's not making pleas for changes away from the current dominant lifestyle.
I can't even get my city to allow basic Japanese style housing, or the type of housing that was commonly built a century ago, with daily needs within convenient walking distance and without threat of massive trucks and SUVs running me over. It's not even legal to build a neighborhood that would fit the Japanese lifestyle in the vast majority of the US.
Perhaps that daily amount of activity is the difference in obesity, perhaps not, but following a typical American diet and the allowed types of transportation is clearly not helping us.
I said directly in my comment "I wholeheartedly agree that the obesity epidemic is a consequence of modern society". And I'm all for making cities more walkable, for example, and making it easier for people to get healthier foods. But I don't think these are realistic options for making a dent in obesity in America any time soon.
If not, are you suggesting you know how to do that? The problem isn't knowing what an individual needs to do. It's knowing how to get an entire country from where we are currently to that point desired point.
What works to keep skinny people skinny won't necessarily make fat people skinny.
That's why some people think things like Ozempic are necessary to deal with obesity in America.