Humans red in tooth and claw

The New Yorker has an interesting article by Manvir Singh about fad diets, with a focus on all-animal diet as ostensibly the diet best suited to our species. A character who brands himself “The Liver King” specifically endorses grassfed beef liver. The paleo diet industry insists that humans evolved to kill animals and devour their tissues and organs, eating plant matter in desperate circumstances.

In reality, the best research we have suggests that humans evolved as omnivores, eating both animal (vertebrate and invertebrate) and plant tissues:
• the tooth wear patterns on fossilized Australopithecus and Neanderthals indicated a diet that contained substantial fibrous plants;
• by comparing diets among 58 foraging societies from around the world, anthropologist Richard Lee found that half got the majority of their calories from plant foods and only eleven relied on hunting for their primary means of subsistence, all but one in the highest or lowest latitudes, far from our African origins;

• the longest-lived humans on the planet today, Japanese from Okinawa, and the population with the lowest incidence of cardiovascular disease, the Tsimane of the Bolivian Amazon, consume diets that are, respectively, nine and fourteen percent protein;
• Most nonhuman primates have a mixed diet that consists of a wide spectrum of plant foods and a relatively small spectrum of animal foods. Patterns of food selection shift in relation to seasonal changes in food availability.
I found the recommendation of liver as heath food particularly odd, considering the liver functions as one of the body’s filtration system to remove toxins from the blood. Why would you eat a toxic waste dump?
I’m not a fan of food as medicine. The first principle is to maintain a healthy weight, which means calories in = calories out. It’s very hard to lose weight though exercise, so a healthy diet should be the focus in that project. Beyond weight, there’s ample evidence that fruits and vegetable calories should displace calories from refined flour and sugar. No more than 20-30% of calories from fat, although there’s not much evidence that, e.g., fat from olive oil is “better” than butterfat.
Beyond that, regular exercise, strong social connections, challenging intellectual activities and good genetics are keys to longer lifespan and longer healthspan. Ignore the fad diets—they’re only designed to lighten your wallet.
https://www.newyorker.com/magazine/2023/10/02/is-an-all-meat-diet-what-nature-intended