The Evolution of the Human Diet: How We Got Here
In 1987 I was living in Spain as part of a medical school exchange program, and
worked in the clinic of a major university hospital. During that time, I rarely
heard a Spaniard of any age—male or female—talk about dieting. The
Mediterranean diet, with all its health benefits, includes the cuisines of Greece,
Italy, and Spain. In Spain, I didn’t see the magnitude of health problems I see
with my patients every single day in America. The Spaniards had no fear of
food, whether it contained fat or carbohydrates. Spaniards eat well, and without
guilt, until they are full. This experience in Spain taught me that the amount of
fat a person consumes isn’t the most important factor—the important contributor
to obesity is “fake food.”
So how did we get the idea that low-fat foods and manufactured fats are good
for us in the first place?
The Paleolithic Diet (2,000,000 to 10,000 BC)
I truly agree with those who say that if we ate like our distant hunter-gatherer
ancestors, most of our health problems—including obesity— would disappear.
During the Paleolithic period, our ancestors followed a lowcarb diet and ate
natural fats. They ate vegetables and nuts, but no grains. They ate fruit, but only
seasonally. Rarely did humans eat sugar, except the natural sugars found in
honey or fruit. Though sparse and primitive, this diet allowed our ancestors to
survive on the earth for millions of years under very harsh conditions. In fact, we
survived even when other animal species couldn’t adapt and became extinct.
Life for early humans centered on a constant struggle to obtain food. The
average life expectancy was very short—probably not beyond age 30. This was
not caused by a poor diet; rather, most succumbed to infections or predators.
During this time, our ancestors developed a taste for animal meat. The
introduction of animal products into the human diet played a major role in our
evolution. The fatty acids found in animal fat served as a new and potent form of
brain food that spurred the development of the human brain. This animal fat also
provided a longer sustained source of energy. Humans, like lions and tigers, no
longer had to eat around the clock to keep up their energy, and they were able to
focus on developing other skills. Unlike true carnivores, however, we retained