The Call, Column 82 – Food for Thought

17 10 2017

(October 15, 2017)

The Urban Farmer

Food for Thought

            What is food?

That’s a question you probably haven’t heard before. And it might have caught you off guard, being that you and I are the Urban Farmer family, and food is kind of our thing.

But really, have you ever actually stopped and thought deeply about food? For me, it took many years of urban farming, developing an environmental awareness, steeping myself in evolutionary/Paleolithic nutrition, reading enough Wendell Berry, and (no word of lie) debating with people in the comment sections of food-related articles to really get me to think deeply about this question. And it’s a rabbit hole that you’ll probably find just as interesting as I do. Grab a flashlight, Alice, because Wonderland awaits!

Let me take you back a few billion years, when the Earth brought forth the first single-celled life. This, I think, is a good starting point for the definition that we’re trying to build today. One of the basic characteristics that defines life is the use of metabolism; that is, taking in energy and materials from the environment in order to support internal functions. This is true of every life-form on the planet, and as far as I’m concerned, it is the basic definition of “food” after all other nuance is stripped away. Food is energy and nutrients from the environment.

The first life on Earth was autotrophic; in addition to taking in materials from its environment, it “created its own energy” by taking in energy from non-living sources, either sunlight (photosynthesis) or chemicals/heat in its environment (chemosynthesis). Plants as well as certain bacteria and algae are autotrophs still present on Earth today.

But, contrary to what some would have you believe, we are not autotrophs. We are heterotrophs, organisms that must steal from, maim, or kill other organisms to supply themselves with energy. Like all other animals, fungus, and some microorganisms, our food must come from the body parts of other living things.

This sort of realization was striking for me, when I made it a year or two ago. There are people who claim that meat/eggs/milk are “not food, they’re murder/theft/etc”. Murder is defined as killing another human being, of course; but inflammatory terminology aside, this sentiment isn’t exactly wrong. ALL of a heterotroph’s food is the product of killing or stealing, by definition, if we believe that these acts are still defined as such when perpetrated against a non-human (they aren’t, but for the sake of argument, let’s broaden their definition). In this scope, “food” doesn’t actually exist. There is no lifeless sludge from which we can extract nourishment (Twinkies notwithstanding). Seeds are the unborn fetuses of plants; fruits are their ovaries; sap is the literal lifeblood (blueberry pancakes with extra syrup, anyone?).

This all might have turned your stomach, but it shouldn’t. We can’t photosynthesize, we can’t live off of volcanic heat, and we aren’t breatharians; for heterotrophs like us, food is the literal bodies of other organisms that contain energy and nutrients.

Getting a little more specific, all of life on Earth is divided into various levels of categorization. The principle, and arguably narrowest of these, is a “species”, a group of very similar organisms that can reproduce with one another.

Among other things, a species is defined by its diet, the things it eats in order to survive. Taking this a little further (warning: justifiable bias ahead), a species’ “optimal diet” is the subset of those things that it CAN eat, in the appropriate amounts necessary to both provide it with all energy and nutrients it needs, in optimal chemical form, but also minimizing its intake of toxins to a manageable level. This optimal diet is developed as an integral part, both a cause and effect, of its evolution.

Wild ruminants eat grass; that’s their optimal diet. They eat grass, because they have multiple stomachs and special bacteria in order to be able to digest grass; because they eat grass; because their stomachs and gut bacteria are supposed to digest grass; because they eat grass. Do you see my point? Their optimal diet developed as an integral part of their evolution. Domesticated cows are also supposed to eat exclusively grass as well, but our government subsidizes corn and soy in order to placate us…so we feed them an evolutionarily-inappropriate diet.

But wild species – animals, plants, fungus, microbes – they basically eat their optimal diets in almost every case. A tree “eats” sunlight and certain soil micronutrients because that’s what its evolutionary history dictates; with low-quality soil, it becomes sickly, and without sunlight, it dies. A robin eats earthworms, seeds, and the bottom half of each perfectly-ripe raspberry in my yard, because that’s what its evolutionary history dictates; if it doesn’t get the protein, fats, carbohydrates, fiber, and beneficial microorganisms that it needs from those foods, its health becomes suboptimal and it becomes more a more likely target for evolutionary purging.

The adherence to optimal, appropriate diet is a benchmark quality of healthy, stable species on Earth. Those individuals that eat appropriately are healthier and better able to survive, reproduce, and teach their offspring to eat similarly; those who don’t, aren’t. For the vast majority of species on earth, essentially all but human beings and their domesticated plants and animals, food is the bodies of the right organisms, in the right amounts.

If the answer to our question, “what is food?”, stopped here, with this last definition, all would be good. This definition is by-and-large the historically- and evolutionarily-normal one, acted upon for basically all of human history (and all of the history of every other species).

But we didn’t stop there. Next time, we will kick off at the start of agriculture, about 10,000 years ago, when the definition of food changed enormously, and has continued to do so throughout written history. Food is a lot more complicated now than ever before. Stay tuned.

My column appears every other Sunday in The Woonsocket Call (also in areas where The Pawtucket Times is available). The above article is the property of The Woonsocket Call and The Pawtucket Times, and is reprinted here with permission from these publications. These are excellent newspapers, covering important local news topics with voices out of our own communities, and skillfully addressing statewide and national news. Click these links to subscribe to The Woonsocket Call or to The Pawtucket Times. To subscribe to the online editions, click here for The Call and here for The Times. They can also be found on Twitter, @WoonsocketCall and @Pawtuckettimes.

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A Paleo/Low-and-Slow-Carb Approach to Produce: Which Fruits and Vegetables are Best?

6 03 2016

This is the product of my new-found obsession with dietary fiber – namely, making sure that I get enough of it, from the best possible dietary sources, coupled with safe amounts of digestible carbohydrates.

I compiled a list of popular vegetables, fruits, and nuts, and parsed through the USDA’s data to find fiber values for different measures of the food – i.e. grams of fiber per cup, and per 100 grams, and per pound. I also calculated the grams of digestible carbohydrate (i.e. {total carbs} – {fiber}) per gram of indigestible fiber, to enumerate those foods which I would consider the “slowest” carbohydrates (with the least digestible carbs per gram of fiber, or equivalently the most fiber per gram of digestible carbs).

My reasoning for this is that fiber acts as a “buffer” of sorts, slowing the digestion and uptake of digestible carbohydrates and minimizing their negative effects on the body’s insulin sensitivity, metabolic health, and the like (not to mention every other benefit fiber consumption has on our metabolic health, starting with our gut bacteria).

With no empirical evidence, but rather a strong hunch, informed by my knowledge of biochemical systems, I hypothesize: on average, a gram of fiber has some “digestible carbohydrate buffer capacity”; so all things being equal, a food with more digestible carbs per gram of fiber has a more negative effect, metabolically, than one with fewer digestible carbs, because the carbohydrates are released into the blood or liver more quickly.

(That’s not to say we shouldn’t eat foods with higher numbers of digestible carbs per fiber, but that the foundation of our copious vegetable consumption should be from foods with lower numbers).

As a quick point of conclusion, I found it pretty remarkable how the true Paleo diet emerges from the table when you sort it by grams of digestible carb per gram of fiber. The foods with the lowest numbers include berries, leafy greens, brassica/cole/cruciferous vegetables (cabbage, broccoli, etc), and nuts and coconuts (I included peanuts in here for arguments’ sake, but they are legumes and there are legitimate reasons to avoid them, beyond the scope of this post). These foods are the closest to their wild ancestors, the plant foods that our bodies evolved to eat (greens, berries, nuts, and tubers, which I’ll discuss below) before agriculture selected for higher levels of sugar at the expense of nutrients.

And without much further ado, I’ve uploaded the chart and made it available below. One discrepancy to point out: it was beyond my level of patience to tease out information about resistant starch – a type of non-fiber carbohydrate that ends up feeding our intestinal bacteria and not our fat cells. This is present in things like tubers (especially potatoes that are raw, or cooked and then cooled in the refrigerator) and onion family vegetables. I’ve made a note in the document, but it’s worth considering onions, leeks, scallions, garlic, and potatoes prepared as described above as having a much lower digestible carb/fiber measure than this table indicates. Eat onions every day, and tubers a few times a week.

Columns A, B, and C are self-explanatory. D through G are the grams of indigestible fiber per common volume or weight measurement of the food (typical “piece”, raw cup, raw 100g, raw 1 lb, respectively). H is the grams of digestible carbs (remember, this includes resistant starch and so skews the numbers of onions and tubers), and I is the important number, grams of digestible carbohydrate per gram of fiber. I have included highlighting – the greener the cell, the less carbs per gram of fiber and therefore, (as per my hypothesis), the better the food.

I urge you to peruse this chart and use it to make the healthiest food choices you can. The USDA (probably erroneously, but still) recommends 14 grams of fiber per 1000 Calorie food intake – about 25 grams per day for a typical woman, and 35 grams per day for a typical man. Armed with the information here, it’s easy to meet or surpass that number – and you’ll quickly see that watermelon probably isn’t the best way to do it.

Happy eating!

Vegetable Fiber Reference – Excel Document

Edit: Here is another version of the table (at the request of a friend of mine) with the rows sorted by grams of fiber per raw cup (first sheet) and grams of digestible carb per gram of fiber (second sheet). You can also change the sorting yourself.

Updated Vegetable Fiber Reference