But isn’t that the tricky part: how do you figure out what is “right”? If you eat synthesized sugar and vitamin C in place of an orange, is it really the same thing? Perhaps the fiber or some other minerals in the orange affect how your body processes and digests the nutrients.
Nutrition is pretty complex and until we know what “right” is, I’d think it’s generally a safer bet to stick with foods that we’ve been eating for hundreds or thousands of years, rather than recently devised nutritive cocktails.
Most modern foods (including unprocessed meat and plants) have only been around for a few hundred years or so.
Not evolutionary change - a. different variery of wheat in your bread.
Personally I also think there is a big difference between selective breeding, and distilling foods into constituent parts in order to recombine in various ways. Maybe I'm overly paranoid, but I don't fully trust humans to understand and play that part of nature just yet.
Classic example being how evolving with meat doesn’t make saturated fat good for us in the long term. And, further, replacing it with modern unsaturated fats (like canola oil) improves health outcomes. Your heuristic of "we've eaten it for a long time so it must be better" doesn't capture that.
Frankly, it seems inevitable that the optimal diet (one that maximizes health through all stages of life) will be a modern artificial one since it seems at its root just a technological problem. But we certainly aren't there yet where we can replace an orange with a synthetic orange pill. That is an interesting world to ponder though.
I think the original point is that virtually everything we eat has "characteristics unfamiliar to our evolutionary history" because the animals and plants we eat have been bred for various characteristics so extensively, so simply avoiding "highly processed foods" doesn't meant that we're eating the types or quantities of foods that humans would have for almost our entire existence
But nobody evolved to eat large quantities of deep fried chicken.
Did your ancestors really eat sourdough for thousands of years in ancient Egypt, or were they hunters or fishermen until more recent times? Agriculture was common but there are societies that don't depend on agriculture, even today.