There have been many articles written about the paleo diet. Almost all of them have been idiotic. GOOD Magazine just did one that is not idiotic. It actually involves talking to actual experts in the field instead of hot physical trainers. This article is an interview with four well-respected physical anthropologists and evolutionary biologists. We have Peter Ungar, author of the excellent Evolution of the Human Diet: The Known, The Unknown, and The Unknowable (a perfect title to describe the field). Also Katherine Milton, who has written some rebuttals to Cordain's papers. Amanda Henry is one of the authors of the infamous paleo "flour" paper I wrote about. I don't know much about Bill Leonard, but his latest papers sound interesting.
Overall, I found Ungar and Leonard's answers the most reasonable. Milton seems to be overreaching both in terms of making inferences based on limited evidence and in terms of her own nutritional expertise. Henry seems fixated on her own paper...
Here are the best quotes:
Leonard: Although there’s an extraordinary range of variation, based on the climate and the environment, hunter-gatherers get a fair amount of meat in their diet. We require a diet that is more energy-dense than other primates and historically, we may have reached that point by incorporating more meat. It’s reflected in evolutionary changes in our face, our teeth, and in our gastrointestinal tract. Indeed, the GI tract of modern humans looks more like a carnivore's than a large primate's. Because early humans increasingly used tools to hunt, we don't show the same kinds of dental adaptations as modern carnivores.
Leonard: There are lots of ways you can improve dietary quality—eating meat, cooking, or processing starchy carbohydrates. These are all human strategies for making food digestible and nutrients more bio-available. To argue that meats are the only strategy is as misguided as thinking that humans were evolved to be folivores, entirely vegetarian.
Ungar: While there’s increasing evidence of meat consumption from the first evidence of butchery 2.5 million years ago to around 1.8 million years ago, when we see sites with lot of bones, we still don’t know how that breaks down in terms of the ratio of meat to plant material. What we do know is that no single food provided a panacea.
Ungar: There was no single Paleolithic diet. Still, I think these are valuable diets in that they remind us what we shouldn’t be eating. Our ancestors didn’t have the processed foods we have today. To say what we should be eating is more difficult, but I can tell you without a shadow of a doubt that australopiths did not eat corn dogs and drink milkshakes.
The worst come from Milton
Milton: Humans evolved to eat a high-quality diet, but that doesn’t mean eating a lot of meat—especially today. Even the Eskimos and Inuits don’t eat a lot of meat. They eat marine mammal fat. No one eats a lot of meat. The only people who eat way too much meat are Americans, who are addicted to eating huge steaks, chops, and roasts.
Um, so animal fat is OK and not meat? Great, I'm a vegan now!
Milton: No matter where they evolved, our diet changed continuously, just like if you’re a primate living in the tropical forest. Every day a monkey in a tree does not eat the same thing; it may eat four or five kinds of leaves, one or two fruits, maybe some flowers. The next day, there’s 50 to 75 percent turnover in what that same monkey is eating and I assume that Paleolithic humans were the same way. Each day, they need to take in a sufficiency of good quality energetic substrate (sugars and starches) and enough protein—say 70 grams or so—to meet their daily requirements for amino acids.
The vast majority of studies on hunter-gatherers show that nearly all of them have staples. Sure, they eat a large variety of plants and animals, but they get most of their calories from a staple source.
Milton: While I don’t know what the paleo diet is, what I do know is that if you’re talking about trying to eat unprocessed foods, a high percentage of fruits and vegetables, and only as much animal source as you need to meet protein and essentially amino acid requirements, then that’s a good diet, especially if you get up and around for an hour each day out in the fresh air.
Yes, because back in the paleolithic when they had killed a mammoth they would stop after eating half and say "Oh, let's leave the rest to the vultures, we've all had our daily 70 grams of protein." Snark. Proves that even scientists can let modern bias stand in the way of science.