Deep within the jungle of Papua New Guinea I gripped a milk-white larvae as its black pinchers pulsed back and forth -- it was dinner. My host Samuel assured me, "take a bite, tastes like chicken!" I was completing the final phase of "Last One Standing," a BBC series that followed six Westerners on a journey to live and eat with 12 tribes around the world. The meal of grubs interested me a bit more than the others -- this journey was my mission to get to the bottom of nutrition.
The traditional peoples of every habitable continent taught me a lot about subsistence -- we threw grenades to catch fish, castrated baby goats, spear-hunted wild boar with rebar poles, even dined on blood and bones. I bore witness to food as a tool for survival.
I returned determined to study more closely how nutrition affected the body at peak performance. I committed to the training regimens of bodybuilders, lifting six days a week, four hours a day, while constantly monitoring the results of changes in my diet.
Protein seemed to be the key ingredient, but I wanted to know why. Through laboratory research, I pursued an objective conclusion on the biochemistry of soy and other protein sources -- only to find myself incredibly frustrated with overly simplistic and inconclusive nutritional lab science.
To discover how it was that science seemed to know so little, but products claimed so much, I earned a living bagging groceries to study the inner workings of our modern food supply system.
What I discovered surprised me: The "secrets" to nutrition I was looking for did not exist -- not hidden in the Amazon, not in carefully calculated protein and vitamin supplements and not in choosing certain packaged foods over others. The nutrition truths that unfolded were simple and profound. Most we've known all along.
Science Can't Tell Us Much About What We Should Eat
The petri dishes, burn calorimeters and lab rats of nutritional science reveal very little about the complex workings of the human body.
One thing we do know: diet matters. Half of worldwide deaths and painful diseases are from causes where diet is a significant risk factor. There are thousands of startling associations between dietary factors and disease.
Pinpointing which of these factors are most useful for improving human health is a different issue. Numerous studies claim that certain foods and behaviors are healthy. Unfortunately, nutrition chemistry is just too complicated to make these claims. Studies are nearly always exaggerated, contradicted or overlook serious confounding factors.
To get accurate data, we would need to directly study humans in a controlled fashion over lifetimes. The barriers are obvious: ethics, willing subjects and a lot of time.
Using this as the standard, I focused my research on the next best things. 1) I observed and shared a hunter-gatherer subsistence diet with 12 tribes around the world. 2) I practiced the athletic training diets developed by elite athletes to manage performance. 3) I studied the conclusions of human nutrition surveys that used the largest sample sizes. 4) I researched the known dietary patterns of our closest relatives, chimpanzees.
The Most Important And Consistent Nutrition Principle
Eat mainly raw fruits and vegetables! We've heard this message our entire lives, but few of us follow it. In fact, we ignore it to our own detriment. This principle has more power to defend our bodies against disease, provide us with stable energy and develop fitness than anything else does. Other diets do some of those things, but only this one does them all, because we have been built for it.
We share 99.7 percent of our DNA with chimpanzees(2). They eat 66 percent fruit, 27 percent vegetables, 3 percent seeds, 4 percent prey -- all of it raw. Our dental formula is exactly the same(3), but our digestive system is about 1/3 smaller(4) because we've developed tools like cooking to make our food denser. Our bodies are engineered for eating mainly fruits and vegetables: about 2/3 raw and 1/3 cooked(5).
It's no fluke that our diet has converged on fruits and veggies. For 100 million years, flowering plants have been perfecting their ovaries to become the most tempting and nutritional food for animals. The better food the plants produce, the more we survive to spread their seeds(6), and the more they survive(7).
And survive they have -- by weight alone, our crops outnumber us by over 20 to 1. Flowering plants have used us to dominate the globe. The champions at this -- tomatoes, apples, carrots, cabbage, citrus, avocados, lettuce, etc. -- have survived because they are our healthiest foods. Healthiest only when they are eaten fresh and raw -- not when canned, juiced, extracted or processed.
We've tried to reproduce the healthy components in the lab, but plants have just been in the game too long. They have developed unique phytonutrients and techniques for high vitamin solubility that we will still be puzzling over for at least the next century. Despite attempts to extract these compounds for supplements, plant nutrients remain much more effective when consumed raw and whole(8).
As a result, raw fruits and vegetables are heroes at fighting disease. People who eat five or more servings daily have half the cancer risk of those who eat only two(9).
Plants Know More Than We Do About What We Should Eat
We humans are organisms at the end of a several-billion-year-long history of evolution. Our window of existence is so very small, and our experience even less. We have a lot of new ideas about nutrition, but most changes in the natural world are harmful to their hosts and we should be cautious about taking our own advice.
When you make choices about things that will directly affect your survival -- like what to put in and on your body -- you should be highly selective. Stick with the things that are tried and true (and I don't mean choose products that have passed seven years of drug testing). The entire science of chemistry has only been around for the last 3 percent of human history, which is only 0.0002 percent of life's history!
The few things that have stood the test of time should be cherished. We know that all animals consistently rely on raw food, lots of water, regular sleep and exercise. These lessons from natural history are the most powerful tools we know. Don't get fooled by efforts to make them more complicated. Return to these principles every time you consider new food products, supplements, diets and even new scientific studies. Despite their claims, most of these things have hidden interests other than your health.
Two years ago I founded the not-for-profit company CORE Foods to try to create a food system without hidden interests. I targeted nutrition bars, because I see their proliferation as a major threat to human health. In the course of this project, I learned many ways in which our modern food system is not the way it seems and I am compelled to share some of my discoveries. Please stay tuned.
Chimps don't consult diet books -- you don't need to, either. We wouldn't be here today if we weren't already experts at these enduring health lessons. With a little information and self-awareness you can reawaken the powerfully honed sense of what is healthy that lies deep within you. Start by considering whether your typical food and lifestyle choices fall within the few enduring health principles that have stood the test of time.
(2) Mary-Claire King, Protein polymorphisms in chimpanzee and human evolution, Doctoral dissertation, University of California, Berkeley (1973).
(3) Peter, Bernhard. (1943) The Evolution of Mammalian Molar Teeth. Boulder, University of Colorado.
(4) Wrangham, Richard. (2010) Cooking with Fire. Houghton Mifflin.
(5) That being said, we can expect to see some changes in our dental formula and physiology as a result of our development of agriculture and industrialization, though it takes about 15-20,000 years for this to occur, and we're not there yet. (Gould, S. J. (2002) The Structure of Evolutionary Theory. Harvard University Press.)
(6) Michael Pollan. (2001) The Botany of Desire. Random House.
(7) Ridley, I.N. (1930) The Dispersal of Plants Throughout the World. Reeve.
(8) Nestle, Marion. (2006). What to Eat. North Point. Page 477
(9) Nestle, Marion. (2006). What to Eat. North Point. Page 62