This is a very cute bunny rabbit munching on some grass. He is an herbivore; he evolved as an herbivore. He eats plant material in his natural habitat. Were you to feed him a diet of nothing but meat he would become very sick, because he is not evolutionarily programmed to eat meat.
This is a lion. Unlike the bunny rabbit, he is a carnivore. He evolved to eat meat. Were you to capture him, put him in a zoo, and feed him nothing but vegetables, he would also become very sick, because he would also be eating counter to his evolution.
And now on to humans. We are also a species of animal, and also subject to the rules of biology and the processes of evolution. So what did we evolve to eat? Homo sapiens, the modern human, first appeared on the African plains some 200,000 years ago. He evolved as a hunter-gatherer, obtaining the majority of his calories through meat (including fatty organ meat and bone marrow – waste not, want not!) and fish, and then supplemented his diet with the fruits, leaves, and root vegetables that he could gather.
What about agriculture, you say? Agriculture was a huge development that changed the course of human evolution. One of the many struggles that our earliest ancestors faced was getting enough calories from their environment. They would have to follow large game herds in order to obtain meat, and many of the plants that they found in their environment, such as grains and beans, were toxic. About 10,000 years ago man discovered that he could cultivate grains and beans, and by cooking them make them edible. They became a cheap, easily obtainable, easy to store, dense source of calories, and agriculture allowed us to settle in one place and build more permanent civilizations. While it was a step forward for human culture, it was a leap backward for health.
While 10,000 years seems like a long time, it is evolutionarily speaking only the blink of an eye. If we were to imagine the entirety of human evolution as one whole year, January 1 until December 31, we started farming sometime on December 31. Our bodies have not had the time to evolve and adjust to a diet based on corn, wheat, and soy, which are present, in one processed form or another, in the vast majority of foods stocking our supermarket shelves. We, like the lions, are still made to be meat eaters.
Not only that, but the cooking processes that render grains and beans edible do not remove all of the toxins from these foods. They still contain quantities of anti-nutrients such as lectins, which cause leaky intestines, stimulate inappropriate insulin responses, and inappropriately activate the immune system, which can often lead to auto-immune disorders, gluten, which causes inflammatory reactions (and not just in people who are diagnosed with celiac disease, but in much of the general population – we are just not designed to digest it), and phytates, which scavenge minerals from the body such as calcium, magnesium, zinc, and iron. They also have a high glycemic index, so they cause spikes and dips in blood sugar, encourage metabolic disregulation, promote weight gain, and increasingly often lead to diabetes. And to top it all off, they are much lower in vitamins and minerals than the traditional human diet. Did you ever wonder why even supposedly “healthy” whole-grain bread has to be fortified? It is because grains are the original empty calories.
So here is a quick and dirty list of what I eat and do not eat, for my optimal health and the optimal health of my baby. I eat as many (organic, pastured) eggs and as much meat as I desire, non-starchy vegetables, especially leafy greens, as many berries as I want, fresh fruit, and occasionally nuts, such as almonds, walnuts, and macadamias (excluding peanuts, which are actually a bean). I do not any eat grains (that means bread, cereal, pasta, cake), sugar, or any refined sweeteners by any other name.
This is only a very brief introduction to nutrition from an evolutionary standpoint. I will leave you today with links to a few of my favorite resources, if you would like to read more in-depth literature. For a brief and easy-to-read introduction to Paleolithic nutrition from a family physician, check out this link. Mark Sisson’s blog, Mark’s Daily Apple, is a wonderful down-to-earth, no-nonsense, easy-to-grasp guide to primal eating and living. One of his best introductory pieces is his Primal Eating Plan. You might also want to check out a more detailed post about Why Grains are Unhealthy.