Of course it isn't true. We evolved in an environment in which food
was scarce and most humans were undernourished. Our ancestors ate meat
whenever they could get their hands on it (which was rare) because
they ate *any* food they could get their hands on. Meat is pretty good
if you are hungry -- its a very concentrated source of nutrients. Even
for people as recently as a century ago in our own culture, meat was
not an everyday thing to find on one's plate.
However, we no longer are living in conditions where food is scarce
and any source of nutrition we can find is to be jumped at. We suffer,
if anything, from overnutrition in our country, with obesity being a
serious cultural concern. We evolved to be able to take advantage of
meat on the rare occassions it was presented to us, but now find
ourselves in conditions where we can eat it every day at every meal if
we so choose. We also evolved, I will point out, with bodies that were
expecting diets that were, for the most part, high in fiber and low in
concentrated protein and fat.
We have thus started to gain all sorts of health problems from eating
a diet we didn't evolve for. We love getting protein because our
ancestors couldn't get enough -- but we get so much more than we need
that it aids and abets osteoporosis. We leap at the chance to consume
fatty foods, given brains programmed to try to get every calorie they
can -- but our bodies aren't tuned for consuming high levels of fat
every day, and although they do a heroic job coping with it, we end up
with heart disease, cancer, and other illnesses as a result. Our
digestive tracts are happy dealing with meat occassionally -- but
forced to cope with low residue foods every day, our long intestinal
tracts, not evolved for such a diet, end up developing unpleasant
problems up to and including colon cancer.
People often ask me "so, if you feel that its okay to eat meat
occassionally and just not every day, why are you such a strict
vegetarian?"
Well, for me, it just simpler to live by a simple rule. This way, I
don't have to try to keep track of how much meat I'm consuming or when
or figure out whether I'm overdoing it, etc. I needn't calorie count,
fat track, or otherwise check over what I'm eating -- I just follow
some simple rules and I'm fine. Given that I know myself well enough
to know that I couldn't obsessively track my dietary intake, this is a
win for me.
I recommend vegan diets largely because they prevent having to deal
with issues of tracking consumption, but for those people who feel
comfortable logging everything they eat, I certainly do not think
there is anything wrong with it -- it just isn't for me.
Perry