When?

I was reading a post by Paul Marik at RealClearHealth on the new generation of anti-obesity drugs hitting the market and read this:

Human beings survived on a diet of mainly lean protein for thousands of years, fasting for most of our waking hours and often eating only one large meal during the day. That changed dramatically in the 20th century, culminating in the U.S. Department of Agriculture publishing a “food pyramid” in 1992 recommending a diet heavy in bread, cereal, rice and grain. Thirty years later, we can see the tragedy of these good intentions. Americans are addicted to carbohydrates and other processed foods that our bodies metabolize as sugar—constantly spiking anxiety, accentuating hunger, and fueling an obesity epidemic that is driving higher rates of chronic disease.

My immediate reaction to that was when was that? The earliest actual examination of a human being’s stomach contents of which I’m aware is that a “bog body” from about 8,000 years ago. Those stomach contents were largely grain. Then there was the examination of the stomach contents of Ötzi the Iceman and that dated from about 5,000 years ago. It showed that he ate a combination of preserved meat and fat, grain, and vegetables. I think it’s pretty well established that after about 8,000 years ago the main component of most human beings’ diets was grain.

The studies of human behavior from the Late Paleolithic (10,000 – 15,000 years ago) of which I’m aware cf. studies by the Braidwoods, found that humans were similarly omnivorous then, preferentially seeking out the protein sources with the highest fat content. That is completely consistent with the high fat content of Ötzi’s last meal.

So, when did human beings subsist primarily on lean protein?

I agree with what I think is the overall premise that we’re eating far too much fat in our diet as well as too much sugar and highly processed grains. I’ve gone so far as to suggest that you won’t go far wrong if you eat what your great-grandparents ate as closely as you’re able to approximate it.

But imagining that human beings behaved in any discernable past in a way that differs drastically from what the best intelligence suggests was the case isn’t particularly helpful.