ultra-processed people by chris van tulleken hypothesizes that it's because the food is less nutritionally dense through extraction and reconstitution to more palatable and economically expedient forms. additionally, these forms require less effort to process by chewing so we're able to ingest more calories more quickly before our biochemistry can catch up and signal that we've consumed what we need. finally, the processing of food breaks down the original nutrient "matrix" in the way that our metabolism evolved to process it. we evolved to metabolize an apple, i believe was his example, by eating it raw and in its original form, together with all that constitutes an "apple" and not simply the composite of nutrients that we can extract from an apple. the hypothesis is that the whole apple influences our biochemical response differently than the extracted nutrients that have been reconstituted in a different form.