Perhaps, but I think we can drill down a bit further.

Many third world countries have foods much, much more processed than we do in USA, yet they don't exhibit such effects generally.

My own family is a huge old Irish/German conglomeration...I have 12 uncles and aunts. There's very clear demarcation of millenials vs the older ones, and especially those raised in a rural setting vs urban.

I'd honestly like to see studies of how many, let's say 'metro' men spent summers bucking hay or stripping tobacco as a kid. I did, but I'm clearly less grizzled than my cousins who did such work year round as a kid.

And I don't mean any of this to be insulting. I'm way less manly than my own father, and a millennial who spent childhood glued to screens.

Why do you describe something like bucking hay or stripling tabacco as 'manly' when it was a common activity for women as well in traditional society?

I don't. I just mentioned them because they are very common labor intensive summer jobs where I grew up. Replace with whatever your local variant would be.