I'm about to say something that is easy to dismiss as bullshit, so feel free to, but you're right, people were healthier in terms of weight in the 60s, and right around that is when we changed dietary guidance to be carb-focused, low fat, etc. Since then, obesity has skyrocketed. The book Obesity Code covers this.

As sibling comments have pointed out, 3800 is availability, not consumption, so it's not an indicator of how much people do eat, just how much they could eat.

You can see it if you watch any US documentary filmed before the late 70s that shows ordinary people in the street. They're much fitter, and exercise for weight loss wasn't really a thing yet; people didn't jog. That's not far enough back that everyone was a farmer or laborer; there were plenty of fairly sedentary office workers. They also weren't starving; it was a prosperous time. They were generally eating meat-and-potatoes diets with plenty of animals fats (I have a 1960s barbeque cookbook that tells you to put a pat of butter on pretty much everything). And obesity wasn't a problem.

And since we started letting the government tell us how to eat healthy, not only has obesity skyrocketed, but so have diseases connected with it.

My parents were vegetarians in the 80s, also no weight issues. I don't believe it's carbs or seed oils or any of the modern scapegoats. Since they were eating plenty of that. They even had cake.

I think it doesn't matter what you eat as long as it isn't super processed. The one thing that's changed a lot in the 90s is more and more convenience food.

"processed" is also a modern scapegoat, unfortunately.

But all three are correct, I think: Food has gotten more laden with sugar, seed oils, and carbs because it's processed to be that way after we tried to go Low Fat for so long.

A conscientious vegetarian is probably eating damn near an ideal diet by avoiding all that.

But they were eating plenty of seed oils, and sugar in cake, and loads of bread.

So mostly carbs, but with a lot of fiber. It just goes counter to the current trend in major ways. I looked through the old cookbooks. The biggest difference is no processed foods. And maybe less microplastics.

It's hard to really appreciate how many calories are added to things like bread, just by virtue of changing the recipe to be more "USA tasty" (e.g., sugary). My EU friends always commented on how sweet everything is in USA, even store-bought bread. If we didn't do that, when we started reducing fat, everything would taste like hardtack. But 200 extra sneaky calories a day + insulin spikes from the refined carbs, and here we are - all fat.

That's true, "bread" in the US is atrocious. I recommend flour, water, salt, yeast. Amazing book if you want to get into home baking.