What is humans natural diet

This could have been a problem since our body needs a certain amount of cholesterol, but our bodies evolved not only to make cholesterol, but also to preserve it and recycle it.

As the editor-in-chief of the American Journal of Cardiology noted 25 years ago, no matter how much fat and cholesterol carnivores eat, they do not develop atherosclerosis. Conversely, within months a fraction of that cholesterol can start clogging the arteries of animals adapted to eating a more plant-based diet. When the average life expectancy is 25 years old, then the genes that get passed along are those that can live to reproductive age by any means necessary, and that means not dying of starvation.

The more calories in food, the better. Eating lots of bone marrow and brains, human or otherwise, would have a selective advantage as would discovering a time machine stash of Twinkies for that matter!

In the 20th century, networks of missionary hospitals in rural Africa found coronary artery disease virtually absent , and not just heart disease, but high blood pressure, stroke, diabetes, common cancers, and more. So we did not need the physiological weaponry other omnivores have, such as bears and dogs. B12 cobalamin is used by every single cell in our bodies, and particularly important for the nervous system. It is created either by the activity of microorganisms certain bacteria and archea.

Many animals have these microorganisms in their guts, because they can be found in the soils where those animals graze, and so they are able to synthesise B12 from their food. Humans, however, do not, and so we must either eat products from animals that do including meat, fish, milk, and eggs , or get it from other sources such as yeast extract or certain seaweed or algae. DHA is an essential omega-3 fatty acid, required for brain development and function. It is found in oily fish such as salmon and some algae.

While the body is able to make some of the DHA it needs from ALA another omega-3 fatty acid , the process is inefficient, so it is hard to get from plants alone. This leads us to the so-called Paleolithic Diet. As a paleoanthropologist I'm often asked for my thoughts about it. I'm not really a fan—I like pizza and French fries and ice cream too much. Nevertheless, diet gurus have built a strong case for discordance between what we eat today and what our ancestors evolved to eat.

It's a compelling argument. Think about what might happen if you put diesel in an automobile built for regular gasoline. The wrong fuel can wreak havoc on the system, whether you're filling a car or stuffing your face. It makes sense, and it's no surprise that Paleolithic diets remain hugely popular. There are many variants on the general theme, but foods rich in protein and omega-3 fatty acids show up again and again.

Grass-fed cow meat and fish are good, and carbohydrates should come from nonstarchy fresh fruits and vegetables. On the other hand, cereal grains, legumes, dairy, potatoes, and highly refined and processed foods are out. The idea is to eat like our Stone Age ancestors—you know, spinach salads with avocado, walnuts, diced turkey, and the like. I am not a dietician and cannot speak with authority about the nutritional costs and benefits of Paleolithic diets, but I can comment on their evolutionary underpinnings.

From the standpoint of paleoecology, the Paleolithic diet is a myth. And Tsimane people who eat market foods are more prone to diabetes than those who still rely on hunting and gathering. For those of us whose ancestors were adapted to plant-based diets—and who have desk jobs—it might be best not to eat as much meat as the Yakut.

Our gut bacteria digest a nutrient in meat called L-carnitine. In one mouse study, digestion of L-carnitine boosted artery-clogging plaque. We had a lot of cavemen out there. In other words, there is no one ideal human diet.

Unfortunately the modern Western diet does not appear to be one of them. The Bajau of Malaysia fish and dive for almost everything they eat. Some live in houses on the beach or on stilts; others have no homes but their boats. The latest clue as to why our modern diet may be making us sick comes from Harvard primatologist Richard Wrangham, who argues that the biggest revolution in the human diet came not when we started to eat meat but when we learned to cook.

Our human ancestors who began cooking sometime between 1. We have evolved to depend upon cooked food. To test his ideas, Wrangham and his students fed raw and cooked food to rats and mice. Mice raised on cooked foods gained 15 to 40 percent more weight than mice raised only on raw food. If Wrangham is right, cooking not only gave early humans the energy they needed to build bigger brains but also helped them get more calories from food so that they could gain weight.

In the modern context the flip side of his hypothesis is that we may be victims of our own success. We have gotten so good at processing foods that for the first time in human evolution, many humans are getting more calories than they burn in a day. If most of the world ate more local fruits and vegetables, a little meat, fish, and some whole grains as in the highly touted Mediterranean diet , and exercised an hour a day, that would be good news for our health—and for the planet.

The Kyrgyz of the Pamir Mountains in northern Afghanistan live at a high altitude where no crops grow. Survival depends on the animals that they milk, butcher, and barter. We follow her to the cooking hut and smell the animals before we see them—three raccoonlike coatis have been laid across the fire, fur and all.

Then they take the carcasses to a stream to clean and prepare them for roasting. First he shot the armadillos as they napped by a stream. Then his dog spotted a pack of coatis and chased them, killing two as the rest darted up a tree.

Alberto fired his shotgun but missed. He fired again and hit a coati.