How "intact" a food is basically how much of the original nutrition remains after processing. Hand milling whole grain into flour is a form of processing, for e

How "intact" a food is basically how much of the original nutrition remains after processing. Hand milling whole grain into flour is a form of processing, for example, that leaves the food almost completely intact because it gets rid of the inedible chaff without destroying much of the bran, germ, and endosperm. Industrially processed all purpose flour, on the other hand, goes through a more destructive process that destroys more of those layers and more of the nutritional value (due to chemicals used, more heat and force generated from machinery, etc). Processing flour into bread, leaves even less of it intact because the yeast and heat irreversibly change the chemistry of the bread, but if the flour is made from intact grains it will be significantly more nutritious, despite roughly the same amount of processing. "intact" food is important because of bioavailability of nutrients as well as metabolic responses like insulin. You can't add fiber or vitamins back into fruit juice with the same effect as eating whole fruit, for example. Edit: Even fully synthesized food that counts as "super duper ultra processed" can be more nutritious than unprocessed food, but as a general rule outside of medicine it isn't.