The Startling Truth Behind the Foods We Eat

Dr. Milton Mills’s Master Class on the Anatomical and Physiological Differences Between Herbivores and Carnivores

• Carnivores prey on animals who flee, so their joints are permanently flexed in a runner’s crouch in order to explode into a quick burst of speed. They don’t, however, have much stamina.

• Herbivores tend to have straight limbs. When they stand, it is the skeleton, rather than the muscles, that resists the force of gravity. That means little muscular energy is required to stand and travel for long distances. Humans are optimized for foraging. We are some of the most efficient long-distance movers on the planet, able to cover very large areas looking for food at a low energy cost.

• Herbivores tend to have small openings to their oral cavities. They have cheek muscles that push the food back to the molars so they can grind and swallow food in soft, chewed balls. Our teeth slide across each other in a horizontal plane. The herbivore jaw is very mobile, which allows rotary motions of chewing, but if an herbivore tries to crush bones or wrestle an animal down with its mouth, it’s probably going to dislocate its jaw, which in the wilderness would mean starving to death.

• Carnivores don’t chew their food. They have a very strong, stable jaw. They have reduced facial musculature, they can open their mouths extremely wide, and their teeth are shaped like steak knives that slide past each other in a vertical plane to slice meat off bone and cut through tough tendons and hides. Their esophagus (the tube connecting the mouth to the stomach) is very stretchy and wide—food rarely gets caught. Human beings frequently choke to death on animal tissue.

• Herbivores have to eat multiple meals every day to get enough calories. By contrast, a typical carnivore can eat 30 percent of their body weight at a single meal; a 300-pound lion can eat 90 to 100 pounds of flesh at one go. Why? Because hunting is very inefficient. Ninety to 95 percent of their hunts are unsuccessful. The average wild carnivore eats once every seven to 10 days.

• Carnivores can eat rotting tissue, which allows them to eat, for example, 100 pounds of flesh from a buffalo and come back the next day to eat another 100 pounds of decomposing flesh.

• The pH of a carnivore’s stomach acid, after eating a meal, is less than or equal to 1.0—comparable to car battery acid, which ranges between 0.8 to 1.0. That’s necessary because, again, they’re eating rotting tissue loaded with bacteria and pathogens. This powerful stomach acid kills the bacteria and also dissolves bone and tough connective tissue.

• When plant eaters (including humans) have food in our stomach, the pH is around 4.5—if it’s a healthy stomach environment. It’s just strong enough to kill certain bacteria found in soil and plants, but not good at killing virulent pathogens.

• Plant eaters need a source of vitamin C because our bodies don’t make it. Vitamin C is widely distributed throughout plant foods. Carnivores make their own vitamin C. We, on the other hand, can take an abundant plant pigment called beta-carotene (which gives color to vegetables like carrots) and convert it into vitamin A. We can make as much vitamin A as we need. Carnivores cannot do this. They have to ingest pre-formed vitamin A, often from animal livers.

• Too much preformed vitamin A is toxic to us. Carnivores can detoxify preformed vitamin A. Herbivores can’t.

• Along the same lines, carnivores can detoxify nitrogenous waste from excess protein. We can’t do that.

• Some plant substances that are extremely beneficial to herbivores are toxic to carnivores. For instance, garlic, onions, and other plants in the allium family have compounds that essentially cause the red blood cells of a cat to explode, and potentially kill them. They can’t detoxify these compounds the way we can. But we not only detoxify them, they actually boost our immune function and help protect us against diseases like cancer.

• Only herbivores have an innate drive to seek out salt. Sodium is a necessary nutrient, and plant tissues are very low in sodium. That’s why we love potato chips, and why cows and deer love saltlicks.

• Carnivores have no innate drive to seek salt. They get plenty of sodium from animal flesh and bodily fluids like blood.