Here's a fun fact for you. Did you know - if it weren't for the fortification in refined grains (in other words, there's vitamins/minerals mixed into enriched flour), the current US nutritional guidelines are SO inadequate that people following them would be deficient in basic nutrients?

That's why, according to the guidelines, you shouldn't eat just unprocessed carbohydrates (like potatoes). At least half of your carbohydrates need to be from enriched flours, because those are fortified.

Of course, this is only required because we're told to severely limit the foods that are actually nutrient dense, like meat and eggs.

This graphic is from https://www.nutritioncoalition.us/