And while correlation does not equal causation, generally eating nutrient - dense food which does not entail any of the foodstuffs that could potentially harm you, is
probably very good
common -
sense advice your grandmother would give you (and for which scientific training is not required to be viewed as preferable).
From those books, I've pulled out all the
advice that's
common to all or most of them, figuring those are
probably the most efficient and effective approaches (they're also the ones that make the most
sense to me).