Liz is right to recommend the Weston Price organization.  The web site is
excellent (for information, you don't need to agree with everything to
value it), but the real gem is in the 1930s book by Weston Price himself:
Nutrition and Physical Degeneration.  Set aside a few evenings and curl up
with this book.  Look at the startling evidence in the photographs. A most
rewarding read.

Keith