I’m thinking it will be the food you eat that gets you. Here’s why.

Humans eat a wide variety of foods; as a species, the diversity of species we eat is greater than any other animal by a very large margin, with the only quirky exception being the animals that we take along with us, the commensals such as rats and cockroaches. Most primates eat a high diversity of foods, but about two million years ago or a bit less, according to the “Cooking Hypothesis” (which a lot of people think is correct) we took an already diverse primate diet and added to it anything we might encounter in the environment that could be made edible with heat and added that to our diet. More recently, beginning about 10,000 years ago, we applied additional technology and the new practice of plant husbandry to convert other foods, some edible some not, into more useful items for our diet. Humans around the world did this independently over several thousand years, in parallel.

Then we got boats that were capable of doing magical things like sailing up wind, and navigation technologies that allowed humans to be less lost when doing so over great distances. Some humans had done this much earlier at a smaller scale, but by the 15th century there were big wooden boats criss crossing the seas, bringing people to places they had never been before, and along with them the foods people ate all over the world.

Have you looked at photographs of traditional people living in traditional, seemingly timeless, ways in places like Africa, the Amazon, or New Guinea? Look again, and focus on the things that form the backdrop for the scenes shown in those photographs. One of the things you’ll see in many pictures is the plantain, or the banana. You might notice the huge elephant ear leaves of taro plants. If you look closely you might notice cassava growing in the fields, or maize.

Maize was domesticated in Mexico, taro, plantains, and bananas in various different locations across south and southeast Asia. Cassava comes from the lowlands of South America, and potatoes come from the Andes. Some Yams come from Africa, some from South America (I oversimplify a bit). You can’t find a modern traditional diet, as it were, that does not include ingredients from continents other than where the traditional diet lives today, except perhaps in Ethiopia. Everybody eats everybody else’s food all the time. The main determinant of where food is grown is not where it was first domesticated, but rather, the limitations of seasons, rainfall, heat and cold. And even there, the limitations are relaxed. Maize only grows in the colder regions because varieties have been developed to do so, and many plants are grown in regions normally too arid for them, by virtue of irrigation.

Adding all this up – the diverse primate diet, the addition of cooked foods otherwise not edible, the artificially selected crops, and the global exchange of horticultural goods and practices – and you get a huge variety of food, the largest variety of food any species has ever managed to include in its diet. (Other than the rats and cockroaches, of course.)

Despite all this diversity, something has remained more or less the same all along. The “traditional” diet for humans, though much altered with cooking, is relatively low quality. I use the term “low quality” in the way an ecologist uses it. How many usable calories do you get out of a kilo of the food item under consideration? Or, related, how much work do you, using food preparation, chewing, and digestion (including the work done by the friendly microbes living in your gut) to convert that kilo of food into energy?

It is easy to see how our traditional diets are low quality by comparing them to the diets of a handful of primates that live almost entirely off of insects, or tree sap, or nectar. If we look at birds, we see the same thing; many species of birds eat pure sugar of one form or another. A few other animals have very high quality diets. Generally, carnivores have higher quality diets than herbivores. There are no carnivores that use multiple stomachs or habitually regurgitates and re-consume their animal prey in order to digest it. Herbivores that eat grass or leaves spend a lot of time feeding, have massive digestive systems designed by natural selection to digest the hell out of the food, and sometimes they have to “eat” the same food multiple times to get enough energy out of it to survive. Humans are somewhere in between. Some of our digestion is done pre-consumption by cooking and processing, but for the most part our natural, traditional diet takes a fair amount of work to process. We don’t live off of sugar water like hummingbirds and many insects do.

And this is why the leading cause of death in the United States and some other countries has shifted from the usual panoply of causes – infectious disease, accident, homicide, etc. – to our diets. Our diet is the most likely thing to kill us, and lately, the primary mediating factor in this particular cause of death is obesity and/or diabetes.

The “traditional” diet of any group of people, as I’ve already outlined, is relatively recent historically, being the result of 10,000 years of developing plants and a few hundred years of transferring crops and growing methods across the world. That traditional diet was prominent globally through the 19th century and well into the 20th century. The food came from farms, and although many amazing novel technologies were being applied on those farms, such as better plows and various other things that could be drawn behind oxen, a team of ponies or horses, or a small tractor, those technologies did not change the diets too much.

But as technologies developed, farms began to scale up. This is the reason that the New England countryside is graced with young forests criss-crossed with quaint stone walls. Those stone walls were field boundaries in the old days. But as farming scaled up, it became economically inviable to have small fields on small farms. A few other things went wrong on some of these New England farms as well, including some climate glitches and some other economic effects that drove farmers off the land and in some cases into cities where there were jobs working in mills. But some of those farmers took part in the great Westward Migrations, as the country grew, and established a new kind of agriculture in the vast regions of the midwest and plaines.

Add a growing urban market for foods, government help in the form of extension and agricultural colleges, more technology such as combines, railroads to move produce to market, mills to process the produce, add some water (irrigation) as needed and salt to taste. It took decades, but we went from an agrarian economy where the same traditional diet we had been eating was produced on a somewhat larger scale, to an agricultural economy that produces mostly one single thing. This product:

OK, I’m exaggerating there. It isn’t really true that the entire US agricultural system has been converted over to the production of sugary drinks. But sometimes it seems that way. Vast expanses of corn are grown in the midwest and plains, and that corn is used to produce vast amounts of ethanol (as fuel), alcoholic beverages, sugary substances including cola, feed for animals, and some of it even makes it to the table as … well, corn. But lets step back to the original comparison of “traditional diet” and the diet many Americans eat today.

When you eat a traditional meal, a good amount of that food is low quality, relatively hard to digest, carbohydrates with a mix of proteins. There will be a little simple sugar here and there and a bit of fat here and there.

The simple sugars go right away to the liver, where they supplement the body’s immediate energy stores. The complex sugars, the carbohydrates that consist of much larger and more involved molecules, take time to digest and break down to eventually use as fuel. So the sugar gives you a small amount of immediate energy and the complex carbohydrates give you energy over the coming hours.

The fats are simply stored up. If you eat fat, the fat molecules are minimally processed, moved to your hips or wherever, and are pasted there for later use. Or, forever, depending.

When you eat a modern diet, it will have two major difference from the traditional diet. The foods at the two ends of that spectrum of availability will be in greater proportion. Instead of having a bunch of low quality food in the middle, with a little fat (for later) on one end of the spectrum, and a little simple sugar (for immediate use) on the other end of the spectrum, the modern diet will have piles of fat and piles of simple sugar and not much in between.

So, what happens? The fat goes where fat goes, as stated already, but there is more of it. The sugar overloads the liver, which detecting an overabundance of energy, converts the sugar to some form of storage, and some of that is fat that joins up with the other fat. There is also a kind of molecule the liver converts some of that sugar into, stored in your liver, for in case you get hungry between meals. That molecule reduces the chance your body will use any of that stored up fat as energy.

Two thousand traditional calories provides you with energy for now, energy for the next several hours, and a bit of energy for much later. Two thousand modern calories provides you with way more energy than you need for now, and a huge amount of fat that you’ll never use because you are never going to let much time go between meals. Because there is a fast food joint just down the street. And your refrigerator and cabinets are full of junk food.

And that’s not all. Our system of agriculture has all sorts of other negatives as well. The following is from the Food and Agriculture page of the Union of Concerned Scientists:

Food and Agriculture: Toward Healthy Food and Farms
Our agricultural system has lost its way.

Millions of acres of corn, soybeans, and other commodity crops, grown with the help of heavy government subsidies, dominate our rural landscapes.

To grow these crops, industrial farms use massive amounts of synthetic fertilizers, herbicides and pesticides, which deplete our soil and pollute our air and water.

Much of this harvest will end up as biofuels and other industrial products—and most of the rest will be used in CAFOs (confined animal feeding operations) or in heavily processed junk foods, which seem cheap only because their hidden costs don’t show up at the cash register.

Industrial agriculture is unhealthy — for our environment, our climate, our bodies, and our rural economies.

A Better Way: Sustainable Agriculture

There’s a better way to grow our food. Working with nature instead of against it, sustainable agriculture uses 21st-century techniques and technologies to implement time-tested ideas such as crop rotation, integrated plant/animal systems, and organic soil amendments.

Sustainable agriculture is less damaging to the environment than industrial agriculture, and produces a richer, more diverse mix of foods. It’s productive enough to feed the world, and efficient enough to succeed in the marketplace—but current U.S. agricultural policy stacks the deck in favor of industrial food production.

… and there is much much more than that, visit the page.

Yesterday, I went to a symposium hosted at the Humphrey Institute at the University of Minnesota and organized by the Center for Science and Democracy at the Union of Concerned Scientists. A description of the symposium is here and the entire thing was “taped” and will be available. I’m not going to tell you anything major about the symposium now; I’ll wait until the video is available, then I’ll provide you with my thoughts on it. For now I’ll just say it was quite good, eye-opening, and that you’ll definitely want to watch it. In fact, you should feel a little bad that you weren’t there.

Stay Tuned.