Tag: Nutrition

Michael Pollan’s Simple Rules for Eating

What if eating right wasn’t actually all that complicated?

What if you read enough to see patterns develop, to realize that when you stripped away all the confusing bits that maybe the skeleton underneath was actually pretty simple?

This is what happened to author Michael Pollan a few years ago when he started doing research to try and figure out what he should be eating.

Most of the time when I embark on such an investigation, it quickly becomes clear that matters are much more complicated and ambiguous — several shades grayer — than I thought going in. Not this time. The deeper I delved into the confused and confusing thicket of nutritional science, sorting through the long-running fats versus carb wars, the fiber skirmishes and the raging dietary supplement debates, the simpler the picture gradually became. I learned that in fact science knows a lot less about nutrition than you would expect – that in fact nutrition science is, to put it charitably, a very young science. It’s still trying to figure out exactly what happens in your body when you sip a soda, or what is going on deep in the soul of a carrot to make it so good for you, or why in the world you have so many neurons – brain cells! – in your stomach, of all places. It’s a fascinating subject, and someday the field may produce definitive answers to the nutritional questions that concern us, but — as nutritionists themselves will tell you — they’re not there yet. Not even close. Nutrition science, which after all only got started less than two hundred years ago, is today approximately where surgery was in the year 1650 – very promising, and very interesting to watch, but are you ready to let them operate on you? I think I’ll wait awhile.

The diet industry brings in billions and billions of dollars every year and some of the latest internet celebrities are food and fitness models/gurus. Is it any surprise? Our survival and well-being depends very largely on our health and (arguably) ours looks. The diet industry taps directly into one of our basic survival instincts. Food is cultural.

There is good money to be had if you can find the magical thing that will help people lose weight and feel better. Unfortunately, there is also good money to be had in treating people for illnesses that occur from poor diet and lack of exercise. In short, complexity is good for business. (This is a misaligned incentive problem of the highest order.)

… consider first the complexity that now attends this most basic of creaturely activities. Most of us have come to rely on experts of one kind or another to tell us how to eat — doctors and diet books, media accounts of the latest findings in nutritional science, government advisories and food pyramids, the proliferating health claims on food packages. We may not always heed these experts’ advice, but their voices are in our heads every time we order from a menu or wheel down the aisle in the supermarket. Also in our heads today resides an astonishing amount of biochemistry. How odd is it that everybody now has at least a passing acquaintance with words like “antioxidant,” “saturated fat,” “omega-3 fatty acids,” “carbohydrates,” “polyphenols,” “folic acid,” “gluten,” and “probiotics”? It’s gotten to the point where we don’t see foods anymore but instead look right through them to the nutrients (good and bad) they contain, and of course to the calories — all these invisible qualities in our food that properly understood, supposedly hold the secret to eating well.

But for all the scientific and pseudoscientific food baggage we’ve taken on in recent years we still don’t know what we should be eating. Should we worry more about the fats or the carbohydrates? Then what about the “good” fats? Or the “bad” carbohydrates, like high-fructose corn syrup? How much should we be worrying about gluten? What’s the deal with artificial sweeteners? Is it really true that this breakfast cereal will improve my son’s focus at school or that other cereal will protect me from a heart attack? And when did eating a bowl of breakfast cereal become a therapeutic procedure, anyway?

For Pollan, the picture actually got clearer the further he traveled down the rabbit hole.

While his research uncovered the fact the we don’t know a whole lot about nutrition — there’s a lot of pseudoscience here — one obvious fact seems to recur: populations that eat a Western diet are generally less healthy than those who eat more traditional diets.

What does Pollan mean by “more traditional diet”?

These diets run the gamut from ones very high in fat (the Inuit in Greenland subsist largely on seal blubber) to ones high in carbohydrate (Central American Indians subsist largely on maize and beans) to ones very high in protein (Masai tribesmen in Africa subsist chiefly on cattle blood, meat, and milk), to cite three rather extreme examples. But much the same holds true for more mixed traditional diets. What this suggests is that there is no single ideal human diet but that the human omnivore is exquisitely adapted to a wide range of different foods and a variety of different diets. Except, that is, for one: the relatively new (in evolutionary terms) Western diet that most of us now are eating.

Research has shown that moving away from the Western diet can reduce your chances of developing the chronic illnesses it causes. Pollan believes this shift is most easily done by coming up with a set of simple rules to govern how we eat and interact with food. (This idea reminded us a lot of Donald Sull’s work in Simple Rules. More specifically his decision rules which help us to set boundaries, prioritize, and know when to stop an action.)

No one is quite sure which parts of the Western diet are the most destructive. There are a lot of confounding variables here — one type of food or macronutrient is tough to isolate. Gary Taubes thinks it’s the easily digestible carbohydrates. Others disagree. And since we’re not quite sure, Pollan thinks we should stick with a set of heuristics to get as close as we can.

Pollan curated these rules into a book called Food Rules: An Eater’s Manual. Let’s take a closer look at some of our favorites.

Don’t Eat Anything Your Great Grandmother Wouldn’t Recognize as Food

Agriculture has come a long way since your great grandmother was born. Many chemicals have been created to both enhance the flavor of food and to help with its shelf life. While all these additives aren’t necessarily bad for you it’s still smart to avoid them most of the time. So if you think great grandma wouldn’t be able to pronounce or understand most of the words on that box of frozen lasagna you’re holding it’s best to pass it up. Speaking of that frozen entree …

Eat Only Foods That Have Been Cooked by Humans.

Pollan means buying raw ingredients and making the food yourself, rather than buying food pre-cooked and pre-packaged. Corporations use too much junk in cooking your food. This is the biggest predictor of a healthy diet.

Eat All the Junk Food You Want as Long as You Cook It Yourself.

This is an interesting rule because generally we are trying to either remove or go around obstacles and in this instance we are very purposefully adding one. If you have a sweet tooth there is nothing wrong with eating cake on occasion. The key here is to eat those unhealthful foods only occasionally. Taking the time to make the food means that you have to be incredibly motivated to have that cake. (And you’re probably not going to whip up a bag of Oreos or potato chips.)

If You’re Not Hungry Enough to Eat an Apple, Then You’re Probably Not Hungry

This is another obstacle style rule, but it also offers you the opportunity to get better in tune with your hunger. Are you grabbing that candy bar from the vending machine at two o’clock in the afternoon because you are hungry or because you do that same thing at two o’clock every day? There are many reasons why we eat and hunger is only one of them.

Stop Eating Before You’re Full

This probably sounds a bit crazy to the average North American. In our society we eat because we are hungry and we stop because we are full. This is our tradition, but in many other cultures the goal of eating is to simply stop the hunger, which is actually quite different. Try this experiment for yourself. Try to wait until you are hungry for your next meal. You want to be able to feel it. Then as you are eating try to be mindful of the moment you stop feeling hungry. You’ll notice that this moment comes quite a few bites before that full feeling comes.

***

Food Rules feels like a succinct tool to help you navigate the confusing nutritional landscape. It’s a quick read that is packed with a lot of information. Imitate Bruce Lee and Absorb what is useful, discard what is useless and add what is specifically your own.

Still Interested? The Omnivore’s Dilemma: A Natural History of Four Meals is one of the best food books we’ve ever read.

Gary Taubes on What Really Makes Us Fat

We’ve been told for decades that dietary fat makes us gain weight, yet research suggests refined carbohydrates are to blame. It’s time to turn the food pyramid upside down. Let’s examine the truth about what causes weight gain – and what we can learn about biases from the field of nutritional science.

Nutrition, as a scientific field, is reminiscent of psychology in its infancy — before Skinner’s or Pavlov’s ideas had made a dent, before there was Piaget, Kahneman, Tversky, Munger; before we had a field called “evolutionary psychology.” Heck, before biology itself had really come to grips with Darwin’s ideas about evolution through natural selection. (That didn’t happen until the modern synthesis in the 1940s.)

There were theories of mind, theories of self, theories of everything, but nearly all of them were incomplete and contradictory explanations of human behavior. Most were unscientific, in the Popperian sense. They couldn’t be falsified, and they claimed to explain too much, even patently opposite behaviors. It would be a long time before we started to pull the threads together and come up with coherent explanations of why we do what we do.

A similar pattern emerges as we survey the field of nutrition today. The ground is not steady. The most widely accepted and promulgated advice of the last fifty years is under attack: Maybe a calorie is not a calorie. Maybe the simple advice of “Eat less, move more,” nice as it sounds, is too simple, and frankly, wrong. (Reminding one of the second half of Einstein’s dictum: As simple as possible, but not simpler.) Maybe saturated fat is actually good for us. Maybe *gasp* salt is actually good for us.

These aren’t slight modifications of a prior theory but a 180-degree turn. (The visual metaphor is more literal than it seems: It’s not hard to argue, with the new evidence, that the old FDA food pyramid we’re familiar with should literally be turned upside down.)

As of late, this heretical thinking has been promoted most heavily by scientific journalist Gary Taubes, with his many articles, and his books: Good Calories, Bad Calories, and the slimmer and more easily digestible Why We Get Fat (And What to Do About It).

He and his intellectual partner, Peter Attia, call it the Alternative Hypothesis. It goes roughly as follows: We don’t gain weight and get modern diseases like heart disease, obesity, and hypertension because we eat too many calories or consume too much dietary fat, but because we are consuming carbohydrates, especially sugar and easily digestible starches, at a pace that nature never intended. The resulting insulin resistance is the main culprit.

In Why We Get Fat, Taubes lays out the modern epidemic:

Fifty years ago, one in every eight or nine Americans would have been officially considered obese, and today it’s one in every three. Two in three are now considered overweight, which means they’re carrying around more weight than the public-health authorities deem to be healthy.

This, in the face of a rise in recreational exercise, gym-going, health-consciousness, and food pyramids. (Not to mention fast food, increasingly sedentary lifestyles, and so on — all the things you’ve heard before. Taubes thinks those are red herrings, by the way.)

The Causality Problem

The premise of the book is relatively simple: Trying to explain the explosion of obesity, hypertension, and heart disease by focusing on overeating or under-exercising (consuming more calories than we’re using) is missing the boat. It’s explaining something causally by simply describing it. Of course, we’re storing more energy than expended. Why?

Step-by-step, detective-like, Taubes explores the current hypotheses and finds them wanting:

…(I will argue) that it is absurd to think about obesity as caused by overeating, because anything that makes people grow–whether in height or weight, in muscle or fat–will make them overeat. Children, for example, don’t grow taller because they eat voraciously and consume more calories than they expend. They eat so much-overeat–because they’re growing. They need to take in more calories than they expend.

We want to know what causes the overeating relative to energy expenditure. Why would any animal or human be driven to store more fat than they needed to function? Wild animals do not carry excess fat unless it has a useful physiological mechanism. (Whales keeping warm, squirrels preparing for winter, etc.)

Many have tried to explain this in psychological terms: Either we’re being manipulated into over-eating, or we’re too weak to resist the temptations of the modern age. Today’s food is just too damn yummy.

Taubes thinks this is the wrong way to approach the problem. What we really need to understand is the regulation of our fat tissue itself and why it would go awry. He calls it Adiposity 101:

The message of eighty years of research on obese animals is simple and unconditional and worth restating: obesity does not come about because gluttony and sloth make it so; only a change in the regulation of fat tissue make a lean animal obese.

The regulation of fat tissue is a bit different than we often imagine. Fat tissue is not like a savings account we add to and then pull from at an indeterminate time later. It’s more like the battery in a solar energy system: It stores excess energy when it is available, then releases it later when the energy isn’t available, at regular periodic intervals.

We’re constantly storing and releasing fat: During every meal, the body mobilizes its resources to store energy not immediately needed. Later, when we’re between meals or sleeping, the body breaks down the stored energy and uses it to fuel the cells. This is how a normally functioning body works. The principle of homeostasis tells us that the body wants to stay in balance: We should be storing only as much fat as needed to survive.

The problem comes when the body isn’t functioning normally, and the balance is lost. We tend to think this happens because we’re overeating. But what if that’s the effect, not the cause? It’s counter-intuitive, but so is the fact that the sun doesn’t revolve around the earth.

The culprit is resistance to insulin, a natural hormone which (among other things) encourages fat storage and discourages the release of fat stores while it’s circulating.

Remember, we depend on fatty acids for fuel in the hours after a meal, as blood sugar levels are dropping to their pre-meal level. But insulin suppresses the flow of fatty acid from the fat cells; it tells the other cells in the body to burn carbohydrates. So, as blood sugar returns to a healthy level, we need a replacement fuel supply.

[…]

(But) if insulin remains elevated, the fat isn’t available…as a result, the cells find themselves starved for fuel, and we quite literally feel their hunger. Either we eat sooner than we otherwise would have or we eat more when we do eat, or both. As I said earlier, anything that makes us fatter will make us overeat in the process. That’s what insulin does.

Taubes thinks we’ve gotten the causality backwards: Overeating doesn’t make us fat any more than overeating makes young children get taller; getting fat causes us to overeat. Our cells are literally being starved for energy by the selfish fat tissue, growing on its own accord in a tumor-like fashion driven by an abundance of circulating insulin. A isn’t causing B…B is causing A. This error has been the source of bad dieting advice.

Resistance is Futile

How do we become insulin resistant in the first place? Simple: We over-consume easily digestible carbohydrates, which causes heavy and constant insulin response in our bloodstream. This level of carbohydrate consumption was not available to our ancestors year-round, making it a modern problem. (One objection that’s been raised here is that our ancestors simply didn’t live long enough to contract modern disease. I hypothesize that there’s an error being made: Many earlier humans lived perfectly long lives, certainly long enough to get obese and hypertensive, but one major reason average life expectancy was low is because child mortality was so high.)

In any case, our cells eventually become resistant to insulin, and as more and more of the hormone is released in response–to keep our blood sugar down–our fat remains stored away tightly in the form of triglycerides (tri = 3 fatty acids, glycerol = a binding molecule; how our body stores fat for later).

The indicators for diseases we now associate with obesity, including hypertension, diabetes, and stroke, have now largely been lumped under the term Metabolic Syndrome. Because these indicators–high triglycerides, high blood pressure, low HDL cholesterol among them–are often associated with an expanding waistline, many have been led to believe that obesity causes the other associated diseases.

Not so, according to Taubes:

The simplest way to look at all these associations, between obesity, heart diseases, type 2 diabetes, metabolic syndrome, cancer, and Alzheimer’s (not to mention the other conditions that also associate with obesity and diabetes, such as gout, asthma, and fatty liver disease), is that what makes us fat–the quality and quantity of carbohydrates we consume–also makes us sick.

The insulin resistance is causing obesity and other problems. It isn’t that A causes B, it’s that C is causing A and B. Another important logical flaw.

What Now?

The implications are fairly obvious, from a diet perspective. We should cut our consumption of carbohydrates drastically, especially those that digest into the blood most easily and cause the most drastic insulin response.

Taubes smartly delimits himself from going beyond that advice, though:

It would be nice if we could improve on the foods to eat, foods to avoid, foods to eat in moderation. Unfortunately, this can’t be done without guessing. The kind of long-term clinical trials have not been undertaken that would tell us more about what constitutes the healthiest variation of a diet in which the fattening carbohydrates have already been removed.

Taubes admits that the right science must be done to prove that he’s right:

Our conventional dietary wisdom, as I’ve described in my books, is based on science that was simply not adequate to the task of establishing reliable knowledge — poorly-controlled human experiments, observational studies incapable of establishing cause and effect, and animal studies that may or may not say anything meaningful about what happens in humans.

That’s why he and Peter Attia created the Nutritional Science Initiative, or NuSi, with the idea of pulling together a range of scientists and researchers to perform more precise experiments. The goal is understanding whether a calorie is really a calorie, whether carbohydrate-restrictive diets are more effective (and why) and a host of other pertinent questions. Only good data will convince the public (and the health officials it turns to for advice) that things need to change. Their work is underway as we write.

Given the resistance most people have to admitting they were wrong, it’s an uphill battle.

***

What makes Taubes an effective thinker, and writer is that he’s pulling from diverse fields in his quest to solve the obesity problem. While nutritionists typically silo themselves, to a certain extent, in their own field, with some influence from psychology to explain why obese people tend to overeat, Taubes instead pulls from anthropology, biochemistry, endocrinology, epidemiology, and the field of nutrition itself. By asking the right questions of the right people, he gets better answers. He isn’t afraid to step on toes. He also uses careful induction, sorting point by point the problems with competing hypotheses. This is something that reminds us of all great thinkers, from Newton to Darwin to Holmes to Munger.

Nutrition is a field changing in real-time: It needs precise thinkers with a strong penchant for self-criticism, truth-seeking, contrarianism, and boundary-crossing. Whether or not Taubes’ Alternative Hypothesis ends up being the correct one, the job needs to be done right. Observational studies, on which most nutritional recommendations are based, are not science: They are hypothesis-generators. Correlation generators. Figuring out causality is a tougher task.

The good news is that this core problem is solvable, and we suspect, like psychology, the field will come together in time.

Article Summary

  • There is no consensus on nutrition research.
  • Despite the rise in gym-going and healthy eating, one in three Americans is considered overweight.
  • The Alternative Hypothesis suggests that modern diseases aren’t because of too many calories but rather because of too many carbohydrates like sugar.
  • According to Taubes, a better understanding of the regulation of fat tissue is the key to unlocking the mysteries of our body.
  • We constantly store and release fat. When we become insulin resistant, the balance is gone and we gain weight.
  • Overeating doesn’t make us fat any more than overeating makes young children get taller; getting fat causes us to overeat.
  • Taubes recommends we cut our consumption of carbohydrates, especially those that digest into the blood most easily and cause the most drastic insulin response.

The Seven Books Bill Gates Thinks You Should Read This Summer

Bill Gates is out with his annual summer reading list and, while longer than last year’s, it’s a great place to kick off your summer reading.

“Each of these books,” Gates writes, “made me think or laugh or, in some cases, do both. I hope you find something to your liking here.”

Hyperbole and a Half, by Allie Brosh.

The book, based on Brosh’s wildly popular website, consists of brief vignettes and comic drawings about her young life. The adventures she recounts are mostly inside her head, where we hear and see the kind of inner thoughts most of us are too timid to let out in public. You will rip through it in three hours, tops. But you’ll wish it went on longer, because it’s funny and smart as hell. I must have interrupted Melinda a dozen times to read to her passages that made me laugh out loud.

The Magic of Reality, by Richard Dawkins.

Dawkins, an evolutionary biologist at Oxford, has a gift for making science enjoyable. This book is as accessible as the TV series Cosmos is for younger audiences—and as relevant for older audiences. It’s an engaging, well-illustrated science textbook offering compelling answers to big questions, like “how did the universe form?” and “what causes earthquakes?” It’s also a plea for readers of all ages to approach mysteries with rigor and curiosity. Dawkins’s antagonistic (and, to me, overzealous) view of religion has earned him a lot of angry critics, but I consider him to be one of the great scientific writer/explainers of all time.

What If?, by Randall Munroe.

The subtitle of the book is “Serious Scientific Answers to Absurd Hypothetical Questions,” and that’s exactly what it is. People write Munroe with questions that range over all fields of science: physics, chemistry, biology. Questions like, “From what height would you need to drop a steak for it to be cooked when it hit the ground?” (The answer, it turns out, is “high enough that it would disintegrate before it hit the ground.”) Munroe’s explanations are funny, but the science underpinning his answers is very accurate. It’s an entertaining read, and you’ll also learn a bit about things like ballistics, DNA, the oceans, the atmosphere, and lightning along the way.

XKCD, by Randall Munroe.

A collection of posts from Munroe’s blog XKCD, which is made up of cartoons he draws making fun of things—mostly scientists and computers, but lots of other things too. There’s one about scientists holding a press conference to reveal their discovery that life is arsenic-based. They research press conferences and find out that sometimes it’s good to serve food that’s related to the subject of the conference. The last panel is all the reporters dead on the floor because they ate arsenic. It’s that kind of humor, which not everybody loves, but I do.

On Immunity, by Eula Biss.

When I stumbled across this book on the Internet, I thought it might be a worthwhile read. I had no idea what a pleasure reading it would be. Biss, an essayist and university lecturer, examines what lies behind people’s fears of vaccinating their children. Like many of us, she concludes that vaccines are safe, effective, and almost miraculous tools for protecting children against needless suffering. But she is not out to demonize anyone who holds opposing views. This is a thoughtful and beautifully written book about a very important topic.

How to Lie With Statistics, by Darrell Huff.

I picked up this short, easy-to-read book after seeing it on a Wall Street Journal list of good books for investors. I enjoyed it so much that it was one of a handful of books I recommended to everyone at TED this year. It was first published in 1954, but aside from a few anachronistic examples (it has been a long time since bread cost 5 cents a loaf in the United States), it doesn’t feel dated. One chapter shows you how visuals can be used to exaggerate trends and give distorted comparisons—a timely reminder, given how often infographics show up in your Facebook and Twitter feeds these days. A useful introduction to the use of statistics, and a helpful refresher for anyone who is already well versed in it.

Should We Eat Meat?, by Vaclav Smil.

The richer the world gets, the more meat it eats. And the more meat it eats, the bigger the threat to the planet. How do we square this circle? Vaclav Smil takes his usual clear-eyed view of the whole landscape, from meat’s role in human evolution to hard questions about animal cruelty. While it would be great if people wanted to eat less meat, I don’t think we can expect large numbers of people to make drastic reductions. I’m betting on innovation, including higher agricultural productivity and the development of meat substitutes, to help the world meet its need for meat. A timely book, though probably the least beach-friendly one on this list.

Here is the video gates showed explaining the reads:

Miracle Grow for Your Brain

spark

Right now the front of your brain is firing signals about what you’re reading and how much of it you soak up has a lot to do with whether there is a proper balance of neurochemicals and growth factors to bind neurons together. Exercise has a documented, dramatic effect on these essential ingredients. It sets the stage, and when you sit down to learn something new, that stimulation strengthens the relevant connections; with practise, the circuit develops definition, as if you’re wearing down a path through a forest.

I’ve talked about how different I feel after yoga or a long walk; things become clearer and I become calmer. The fascinating book Spark: The Revolutionary New Science of Exercise and the Brain, by John Ratey, explains biologically what accounts for these significant changes in our mind and body.

This is your brain on exercise.

… physical activity sparks biological changes that encourage brain cells to bind to one another. For the brain to learn, these connections must be made; they reflect the brain’s fundamental ability to adapt to challenges. The more neuroscientists discover about this process, the clearer it becomes that exercise provides an unparalleled stimulus, creating an environment in which the brain is ready, willing, and able to learn. Aerobic activity has a dramatic effect on adaptation, regulating systems that might be out of balance and optimizing those that are not – it’s an indispensable tool for anyone who wants to reach his or her full potential.

Exercise can have a dramatic affect on our ability to learn.

Darwin taught us that learning is the survival mechanism we use to adapt to constantly changing environments. Inside the microenvironment of the brain, that means forging new connections between cells to relay information. When we learn something, whether it’s a French word or a salsa step, cells morph in order to encode that information; the memory physically becomes part of the brain.

Exercise affects how primed our brain is to take on this new information and create these new connections. If you think of your mind as a garden, the more you move, the more you enrich the soil with positive neurotransmitters like dopamine (attention, motivation, pleasure), serotonin (mood, self-esteem, learning), and norepinephrine (arousal, alertness, attention, mood). More importantly you sprinkle the ground with something called ‘brain-derived neurotrophic factor (BDNF), a protein produced inside nerve cells which Ratey has dubbed ‘Miracle-Gro for the brain.’

Researchers found that if they sprinkled BDNF onto neurons in a petri dish, the cells automatically sprouted new branches, producing the same structural growth required for learning.

Spark goes into detail regarding the types of exercise that best produce this cocktail of neurotransmitters and proteins for your brain to sip on but at the end of the day any movement is good, especially if it’s something you want to do.

“Experiments with lab rats suggest that forced exercise doesn’t do the trick quite like voluntary exercise”

So next time you get in a bit of a rut or you simply want to maximize your potential, get up and get moving.

Ancient Wisdom For Lifelong Health

I was excited to read John Durant’s book The Paleo Manifesto: Ancient Wisdom for Lifelong Health. Whether or not you’re interested in paleo, it’s full of interesting nuggets.

Especially the part where Durant explains how fasting can help fight infections.

One indication of this effect comes from the behavior of sick animals, including humans, who often lose their appetite until an illness has passed. Farm animals, pets, zoo animals, and wild animals often just stop eating altogether when facing an acute infection or a serious injury. The widespread nature of this phenomenon suggests it’s an adaptive response. Loss of appetite isn’t a bug, it’s a feature.

Like attacking the supply lines of an invading army, dietary restriction weakens pathogens while the immune system mounts a counteroffensive. Tiny pathogens don’t have large nutrient reserves and rely on the host for nutrition—therefore manipulating our nutrition is a way to manipulate their nutrition.

This may help explain why religious fasting became so prominent.

The benefits of fasting transcend chronic infections. It’s one of the promising areas of cancer research, especially in response to chemo.

“Fasting alters the playing field by activating ancient starvation defences in the cell. Fasting is a signal to the body that resources are scarce. Healthy, nonmalignant cells take the hint and stop dividing as often, focusing instead on cellular repair mechanisms that conserve resources. So even as chemo damages healthy cells, they are hard at work repairing chromosomal damage. But malignant cells don’t stop dividing; they’re “cancerous” because they refuse to do anything but grow and grow.

This part on gluten was also interesting.

In wheat, for example, gluten makes up the majority of wheat protein. Even though gluten is associated with the small percentage of people with celiac disease, it causes gut inflammation in over 80% of people. The gut is the digestive tract, which plays a central role not only in digestion, but in metabolism and immune function as well. Persistent gut inflammation can damage intestinal lining, and large molecules and bacteria can ooze out into the bloodstream—which initiates a reaction from the immune system. Autoimmune disorders occur when the body chronically attacks itself, and a wide variety—lupus, type 1 diabetes, and multiple sclerosis—are associated with a leaky, inflamed gut and wheat consumption.”

The book is broken into three parts. The first part is a brief history of humanity through five ages of existence—Animal, Paleolithic, Agricultural, Industrial, and Information. Each of these stages provides lessons for how we can be healthier today. The second part looks at how we can apply these lessons to “multiple areas of modern-day life: food, fasting, movement, bipedalism (standing, walking, running), temperature, sun, and sleep.” The book wraps up with a speculative vision of how our ancient hunter and gatherer roles can inspire us to build healthy lifestyles.

Durant started eating paleo in September of 2006 and some amazing things started to happen. After ten days

“I had much more consistent energy throughout the day. There was no more “head on the desk” after lunch. My mood improved, too. I felt more confident and optimistic. When something negative occurred in my life, I found that I was able to weather it with greater ease. The energy and mood gains in and of themselves were enough to tell me I was on the right track. … Due to the low sugar content in my diet, I stopped getting a thin filmy residue on my teeth. Industrial food started tasting way to sweet, and I came to enjoy natural flavors more. I lost the cravings for refined carbs — cookies, cupcakes, pasta, muffins, and bagels — and I found bready foods to be both salty and bland. My immune system improved dramatically.

Overall, it felt like walking up from a perpetual state of hangover. And once I knew what “good” felt like, it made “bad” feel a whole lot worse.

When it comes to a healthy diet and overall lifestyle, here are Durant’s 5 recommendations.

1. What to Eat: Mimic a Hunter-Gatherer (or Herder) Diet

Stop counting calories. Eat the right foods: meat, seafood, roots and tubers, leafy vegetables, eggs, fruit, and nuts. Experiment with full- fat fermented dairy. Aim for a diet where the bulk of calories comes from seafood and animals, but the physical bulk comes from plants. Don’t be afraid of fat, eat nose to tail, and eat a variety of plants.

2. How to Eat: Follow Ancient Culinary Traditions

Respect ancient culinary wisdom. Follow traditional recipes. Eat fermented foods (sauerkraut, kimchi). Eat raw foods (sashimi, ceviche, tartare). Make broths and stocks. Cook at low heat, using traditional fats and oils (coconut oil, beef tallow, butter, ghee, olive oil). Eat your colors. Eat time-honored “superfoods”: liver, eggs, seaweed, cold water fish. Enjoy real butter. Salt to taste. Drink tea.

3. What Not to Eat: Avoid Industrial Foods, Sugars, and Seeds

Avoid processed foods of the Industrial Age, including sugar (sweetened foods, table sugar, dried fruit, plus artificial sweeteners) and vegetable oils (canola oil, soybean oil, corn oil, peanut oil). Avoid eating large, concentrated quantities of the seed-based crops of the Agricultural Age, such as grains (wheat, corn, barley, oats) and legumes (soy, beans, peanuts). If grains are eaten, go with rice.

Beverages: Drink water as thirsty. Drink traditional beverages in moderation, if desired (tea, coffee, wine, alcohol, milk). Avoid industrial beverages (soda, energy drinks, skim milk).

4. Make It Meaningful: Experiment, Customize, Enjoy

Use these guidelines as a starting point for your own experimentation. Modify according to your own health, goals, tastes and preferences, background, and budget. Make your diet meaningful (family recipes, ethnic cuisine). Be comfortable breaking away from it to enjoy life (celebrations, unique experiences).

5. Lead a Healthy Lifestyle

Sleep as much as possible. Move and exercise regularly. Stay on your feet (stand, walk, run). Get regular, moderate sun. Try some intermittent fasting. Try some hot and cold exposure. Make it meaningful in order to make it an ongoing lifestyle.

If you’re looking for diet tips, Durant personally follows the guidelines in Perfect Health Diet by Drs. Paul and Shou-Ching Jaminent.

No, this is not another paleo diet book; It is a lifestyle book full of ancient wisdom and practical advice on everything from diet and sunscreen to barefoot running and screen time. It just might change your life.

Vaclav Smil: Should We Eat Meat? Evolution and Consequence of Modern Carnivory

What can and should be done about human carnivory? Vaclav Smil answers in this adapted excerpt from Should We Eat Meat?: Evolution and Consequences of Modern Carnivory:

There is no doubt that human evolution has been linked to meat in many fundamental ways. Our digestive tract is not one of obligatory herbivores; our enzymes evolved to digest meat whose consumption aided higher encephalization and better physical growth. Cooperative hunting promoted the development of language and socialization; the evolution of Old World societies was, to a significant extent, based on domestication of animals; in traditional societies, meat eating, more than the consumption of any other category of foodstuffs, has led to fascinating preferences, bans and diverse foodways; and modern Western agricultures are obviously heavily meat-oriented. In nutritional terms, the links range from satiety afforded by eating fatty megaherbivores to meat as a prestige food throughout the millennia of preindustrial history to high-quality protein supplied by mass-scale production of red meat and poultry in affluent economies.

But is it possible to come up with a comprehensive appraisal in order to contrast the positive effects of meat consumption with the negative consequences of meat production and to answer a simple question: are the benefits (health and otherwise) of eating meat greater than the undesirable cost, multitude of environmental burdens in particular, of producing it?

Killing animals and eating meat have been significant components of human evolution that had a synergistic relationship with other key attributes that have made us human, with larger brains, smaller guts, bipedalism and language. Larger brains benefited from consuming high-quality proteins in meat-containing diets, and, in turn, hunting and killing of large animals, butchering of carcasses and sharing of meat have inevitably contributed to the evolution of human intelligence in general and to the development of language and of capacities for planning, cooperation and socializing in particular. Even if the trade-off between smaller guts and larger brains has not been as strong as is claimed by the expensive-tissue hypothesis, there is no doubt that the human digestive tract has clearly evolved for omnivory, not for purely plant-based diets. And the role of scavenging, and later hunting, in the evolution of bipedalism and the mastery of endurance running cannot be underestimated, and neither can the impact of planned, coordinated hunting on non-verbal communication and the evolution of language.

Homo sapiens is thus a perfect example of an omnivorous species with a high degree of natural preferences for meat consumption, and only later environmental constraints (need to support relatively high densities of population by progressively more intensive versions of sedentary cropping) accompanied by cultural adaptations (meat-eating restrictions and taboos, usually embedded in religious commandments) have turned meat into a relatively rare foodstuff for majorities of populations (but not for their rulers) in traditional agricultural societies. Return to more frequent meat eating has been a key component of a worldwide dietary transition that began in Europe and North America with accelerating industrialization and urbanization during the latter half of the 19th century. In affluent economies, this transition was accomplished during the post-WW II decades, at a time when it began to unfold, often very rapidly, in modernizing countries of Asia and Latin America.

As a result, global meat production rose from less than 50 t in 1950 to about 110 t in 1975; it doubled during the next 25 years, and by 2010 it was about 275 t, prorating to some 40 g/capita, with the highest levels (in the US, Spain and Brazil) in excess of 100 g/capita. This increased demand was met by a combination of expanded traditional meat production in mixed farming operations (above all in the EU and China), extensive conversion of tropical forests to new pastures (Brazil being the leader) and the rise of concentrated animal feeding facilities (for beef mostly in North America, for pork and chicken in all densely populated countries).

This, in turn, led to a rise of modern mass-scale feed industry that relies primarily on grains (mainly corn) and legumes (with soybeans dominant, fed as a meal after expressing edible oil) combined with tubers, food-processing residues and many additives to produce a variety of balanced feedstuffs containing optimal shares of carbohydrates, proteins, lipids and micronutrients (and added antibiotics). But it has also led to a widespread adoption of practices that create unnatural and stressful conditions for animals and that have greatly impaired their welfare even as they raised their productivity to unprecedented levels (with broilers ready for slaughter in just six to seven weeks and pigs killed less than six months after weaning).

Meat is undoubtedly an environmentally expensive food. Large animals have inherently low efficiency of converting feed to muscle, and only modern broilers can be produced with less than two units of feed per unit of meat. This translates into relatively large demands for cropland (to grow concentrates and forages), water, fertilizers and other agrochemicals, and other major environmental impacts are created by gaseous emissions from livestock and its wastes; water pollution (above all nitrates) from fertilizers and manure is also a major factor in the intensifying human interference in the global nitrogen cycle.

Opportunities for higher efficiency can be found all along the meat production–consumption chain. Agronomic improvements – above all reduced tillage and varieties of precision cropping (including optimized irrigation) – can reduce both the overall demand for natural resources and energy inputs required for feed production while, at the same time, improving yields, reducing soil erosion, increasing biodiversity and minimizing nitrogen leakage (Merrington et al. 2002). Many improvements can lower energy used in livestock operations (Nguyen et al. 2010), reduce the specific consumption of feed (Reynolds et al. 2011) and minimize environmental impacts of large landless livestock facilities (IST 2002). Considerable energy savings can also be realized by using better slaughter and meat processing methods (Fritzson and Berntsson 2006).

Rational meat eating is definitely a viable option.

Toward Rational Meat Eating

We could produce globally several hundred millions of tons of meat without ever-larger confined animal feeding operations (CAFOs), without turning any herbivores into cannibalistic carnivores, without devoting large shares of arable land to monocropping that produces animal feed and without subjecting many grasslands to damaging overgrazing – and a single hamburger patty does not have to contain meat from several countries, not just from several cows. And there is definitely nothing desirable to aim for ever higher meat intakes: we could secure adequate meat supply for all of today’s humanity with production methods whose energy and feed costs and whose environmental impacts would be only a fraction of today’s consequences.

Meat consumption is a part of our evolutionary heritage; meat production has been a major component of modern food systems; carnivory should remain, within limits, an important component of a civilization that finally must learn how to maintain the integrity of its only biosphere.

The most obvious path toward more rational meat production is to improve efficiencies of many of its constituent processes and hence reduce waste and minimize many undesirable environmental impacts. As any large-scale human endeavor, meat production is accompanied by a great deal of waste and inefficiency, and while he have come close to optimizing some aspects of the modern meat industry, we have a long way to go before making the entire enterprise more acceptable. And, unlike in other forms of food production, there is an added imperative: because meat production involves breeding, confinement, feeding, transportation and killing of highly evolved living organisms able to experience pain and fear, it is also accompanied by a great deal of unnecessary suffering that should be eliminated as much as possible.

Opportunities to do better on all of these counts abound, and some are neither costly nor complicated: excellent examples range from preventing the stocking densities of pastured animals from surpassing grassland’s long-term carrying capacity to better designs for moving cattle around slaughterhouses without fear and panic. There is no shortage of prescriptions to increase global agricultural production with the maintenance of well-functioning biosphere or, as many of my colleagues would say, to develop sustainable food production while freezing agriculture’s environmental footprint of food (Clay 2011) – or even shrinking it dramatically (Foley et al. 2011).

The two key components in the category of improvements are the effort to close yield gaps due to poor management rather than to inferior environmental limitations and to maximize the efficiency with which the key resources are used in agricultural production. Claims regarding the closing of the yield gaps must be handled very carefully as there are simply too many technical, managerial, social and political obstacles in the way of replicating Iowa corn yield throughout Asia, to say nothing about most of sub-Saharan Africa, during the coming generations. Africa’s average corn yield rose by 40% between 1985 and 2010 to 2.1 /ha, far behind the European mean of 6.1 and the US average of 9.6 /ha, but even if it were double during the next 25 years to 4.2 /ha, the continent’s continuing rapid growth would reduce it to no more than about 35% gain in per capita terms. Asian prospects for boosting the yields are better, but in many densely populated parts of that continent, such yields might be greatly reduced, even negated by the loss of arable land to continuing rapid urbanization and industrialization.

At the same time, there does not appear to be anything in the foreseeable future that could fundamentally change today’s practices of growing livestock for meat. Indeed, many arguments can be made that after half a century of focused breeding, accelerated maturation of animals and improvements in feed conversion, these advances have gone too far and are now detrimental to the well-being of animals and to the quality of the food chain and have raised environmental burdens of meat production to an unprecedented level that should not be tolerated in the future. And neither the expanded aquaculture nor plant-based meat imitations will claim large shares of the global market anytime soon, and cultured meat will remain (for a variety of reasons) an oddity for a long time to come.

Consequently, it is very unlikely that the undoubted, continuing (and possibly even slightly accelerating) positive impact of the combination of higher productivities, reduced waste, better management and alternative protein supplies would make up for additional negative impacts engendered by rising meat production and that there would be discernible net worldwide improvement: the circle of reduced environmental impacts cannot be squared solely by more efficient production. At the same time, the notion that an ideal form of food production operating with a minimal environmental impact should exclude meat – nothing less than enacting “vegetarian imperative” (Saxena 2011) on a global scale – does not make sense.

This is because both grasslands and croplands produce plenty of phytomass that is not digestible by humans and that would be, if not regularly harvested, simply wasted and left to decay. In addition, processing of crops to produce milled grains, plant oils and other widely consumed foodstuffs generates a large volume of by-products that make (as described in Chapter 4) perfect animal feeds. Rice milling strips typically 30% of the grain’s outermost layers, wheat milling takes away about 15%: what would we do with about 300 Mt of these grain milling residues, with roughly the same mass of protein-rich oil cakes left after extraction of oil (in most species accounts for only 20–25% of oilseed phytomass), and also with the by-products of ethanol (distillers grain) and dairy industries (whey), waste from fruit and vegetable canning (leaves, peels), and citrus rinds and pulp?

They would have to be incinerated, composted or simply left to rot if they were not converted to meat (or milk, eggs and aquacultured seafood). Not tapping these resources is also costly, particularly in the case of porcine omnivory that has been used for millennia as an efficient and rewarding way of organic garbage disposal. Unfortunately, in 2001, the EU regulations banned the use of pig swill for feeding, and Stuart (2009) estimated that this resulted in an economic loss of €15 billion a year even when not counting the costs of alternative food waste disposal from processors, restaurants and institutions. Moreover, the ban has increased CO2 emissions as the swill must be replaced by cultivated feed.

At the same time, given the widespread environmental degradation caused by overgrazing, the pasture-based production should be curtailed in order to avoid further soil and plant cover degradation. Similarly, not all crop residues that could be digested by animals can be removed from fields, and some of those that can be have other competing uses or do not make excellent feed choices, and not all food processing residues can be converted to meat. This means that a realistic quantification of meat production potential based on phytomass that does not require any cultivation of feed crops on arable land cannot be done without assumptions regarding their final uses, and it also requires choices of average feed conversion ratios. As a result, all such calculations could be only rough approximations of likely global totals, and all of my assumptions (clearly spelled out) err on a conservative side.

Because most of the world’s grasslands are already degraded, I will assume that the pasture-based meat production in low-income countries of Asia, Africa and Latin America should be reduced by as much as 25%, that there will be absolutely no further conversion of forests to grasslands throughout Latin America or in parts of Africa, and that (in order to minimize pasture degradation in arid regions and nitrogen losses from improved pastures in humid areas) grazing in affluent countries should be reduced by at least 10%. These measures would lower pasture-based global beef output to about 30 t/year and mutton and goat meat production to about 5 t.

Another way to calculate a minimum production derived from grasslands is to assume that as much as 25% of the total area (the most overgrazed pastures) should be taken out of production and that the remaining 2.5 ha would support only an equivalent of about half a livestock unit (roughly 250 g of cattle live weight) per hectare (for comparison, since 1998 the EU limits the grazing densities to 2 U/ha, Brazil’s grasslands typically support 1 U/ha and 0.5 U is common in sub-Saharan Africa). Assuming average annual 10% off-take rate and 0.6 conversion rate from live to carcass weight, global meat production from grazing would be close to 40 t/year, an excellent confirmation of the previous total derived by different means.

At the same time, all efforts should be made to feed available crop residues to the greatest extent possible. Where yields are low and where the cultivated land is prone to erosion, crop residues should be recycled in order to limit soil losses, retain soil moisture and enrich soil organic matter. But even with much reduced harvest ratios of modern cultivars (typically a unit of straw per unit of grain), high yields result in annual production of 4–8  of straw or corn stover per hectare, and a very large part of that phytomass could be safely removed from fields and used as ruminant feed. The annual production of crop residues (dominated by cereal straws) now amounts to roughly 3 Gt of dry phytomass.

Depending on crops, soils and climate, recycling should return 30–60% of all residues to soil, and not all of the remaining phytomass is available for feeding: crop residues are also used for animal bedding; for many poor rural families in low-income countries, they are the only inexpensive household fuel; and in many regions (in both rich and poor countries) farmers still prefer to burn cereal straw in the fields – this recycles mineral nutrients but it also generates air pollution. Moreover, while oat and barley straws and stalks and leaves of leguminous crops are fairly, or highly, palatable, ruminants should not be fed solely by wheat or rice straw; rice straw in particular is very high in silica (often in excess of 10%), and its overall mineral content may be as high as 17%, more than twice that of alfalfa. As a result, the best use of cereal straws in feeding is to replace a large share (30–60%) of high-quality forages.

These forages should be cultivated preferably as leguminous cover crops (alfalfa, clovers, vetch) in order to enhance the soil’s reserves of organic matter and nitrogen. If only 10% of the world’s arable land (or about 130 ha) were planted annually with these forage crops (rotated with cereals and tubers), then even with a low yield of no more than 3 /ha of dry phytomass, there would be some 420 t of phytomass available for feeding, either as fresh cuttings or as silage or hay. Matching this phytomass with crop residues would be quite realistic as 420 t would be only about 15% of the global residual phytomass produced in 2010. Feeding 840 t of combined forage and residue phytomass would, even with a very conservative ratio of 20 g of dry matter/kg of meat (carcass weight), produce at least 40 t of ruminant meat.

Unlike in the case of crop residues, most of the food processing residues are already used for feeding, and the following approximations quantify meat production based on their conversion. Grain milling residues (dominated by rice and wheat) added up to at least 270 t in 2010, and extraction of oil yielded about 310 t of oil cakes. However, most of the latter total was soybean cake whose output was so large because the crop is now grown in such quantity (about 260 t in 2010) primarily not to produce food (be it as whole grains, fermented products including soy sauce and bean curd, and cooking oil) but as a protein-rich feed.

When assuming that soybean output would match the production of the most popular oilseed grown for food (rapeseed, at about 60 t/year), the worldwide output of oil cakes would be about 160 t/year. After adding less important processing by-products (from sugar and tuber, and from vegetable and fruit canning and freezing industries), the total dry mass of highly nutritious residues would be about 450 t/year of which some 400 t would be available as animal feed. When splitting this mass between broilers and pigs, and when assuming feed : live weight conversion ratios at, respectively, 2 : 1 and 3 : 1 and carcass weights of 70% and 60% of live weight, feeding of all crop processing residues would yield about 70 t of chicken meat and 40 t of pork.

The grand total of meat production that would come from grazing practiced with greatly reduced pasture degradation (roughly 40 t of beef and small ruminant meat), from feeding forages and crop residues (40 t of ruminant meat) and from converting highly nutritious crop processing residues (70 t chicken meat and 40 t pork) would thus amount to about 190 t/year. This output would require no further conversions of forests to pastures, no arable land for growing feed crops, no additional applications of fertilizers and pesticides with all the ensuing environmental problems. And it would be equal to almost exactly two-thirds of some 290 t of meat produced in 2010 – but that production causes extensive overgrazing and pasture degradation, and it requires feeding of about 750 t of grain and almost 200 t of other feed crops cultivated on arable land predicated on large inputs of agrochemicals and energy.

And the gap between what I call rational production and the actual 2010 meat output could be narrowed. As I have used very conservative assumptions, every component of my broad estimate could be easily increased by 5% or even 10%. Specifically, this could be achieved by a combination of slightly higher planting of leguminous forages rotated with cereals, by treatment of straws with ammonia to increase its nutrition and palatability, by a slightly more efficient use of food processing by-products and also by elimination of some of the existing post-production meat waste. Consequently, the total of 200 t/year can be taken as an unassailably realistic total of global meat output that could be achieved without any further conversion of natural ecosystems to grazing land, with conservative pasture management, and without any direct feeding of grains (corn, sorghum, barley), tubers or vegetables, that is, without any direct competition with food produced on arable land.

This amounts to almost 70% of the actual meat output of about 290 t in the year 2010: it would not be difficult to adjust the existing system in the described ways, eliminate all cultivation of feed crops on arable land (save for the beneficial rotation with leguminous forages) and still average eating only a third less meat than we eat today.

A key question to ask then is how the annual total of some 200 t of meat would compare with what I would term a rational consumption of meat rather than with the existing level. Making assumptions about rational levels of average per capita meat consumption is done best by considering actual meat intakes and their consequences. A slight majority of people in France, the country considered to be a paragon of classic meat-based cuisine, now eat no more than about 16 g of meat a year per capita, and the average in Japan, the nation with the longest life expectancy, is now about 28 g of meat (both rates are for edible weight). Consequently, I will round these two rates and take the per capita values of 15–30 g/year as the range of rational meat consumption. For seven billion people in 2012, this would translate to between 105 and 210 Mt/year – or, assuming 20/30/50 beef/pork/chicken shares, between 140 and 280 Mt in carcass weight. The latter total is almost equal to the actual global meat output in 2010, with the obvious difference being that the consumption of today’s output is very unevenly distributed.

If we could produce 200 t/year without any competition with food crops, then the next step is to inquire how much concentrate feed we would need to grow if we were to equal current output of roughly 300 t with the lowest possible environmental impact. Assuming that the additional 100 t meat a year would come from a combination of 10 t of beef fed from expanded cultivation of leguminous forages, 10 t of herbivorous fish (conversion ratio 1 : 1) and 80 t of chicken meat (conversion ratio 2 : 1), its output would require about 170 t of concentrate feed, that is, less than a fifth of all feed now produced on arable land. Moreover, a significant share of this feed could come from extensive (low-yield and hence low-impact) cultivation of corn and soybeans on currently idle farmland.

Roques et al. (2011) estimated that in 2007 there were 19–48 Mha of idle land (an equivalent of 1.3–3.3% of the world’s arable area), that is, land cultivated previously that can be planted again, most of it in North America and Asia. Using 20 ha of this land would produce at least an additional 60 t of feed. And when factoring in increasing crop yields, regular rotations with leguminous forages (producing excellent ruminant feed while reducing inputs of nitrogen fertilizers) and, eventually, slightly higher feed conversion efficiencies, it is realistic to expect that the share of the existing farmland used to grow feed crops could be reduced from the current share of about 33% to less than 10% of the total. Consequently, there is no doubt that we could match recent global meat output of about 300 t meat a year without overgrazing, with realistically estimated feeding of residues and by-products, and with only a small claim on arable land, a combination that would greatly limit livestock’s environmental impact.

Prospects for Change

Many years ago, I decided not to speculate about the course and intensity of any truly long-term developments: all that is needed to show a near-complete futility of these efforts is to look back and see to what extent would have any forecast made in 1985 captured the realities of 2010 – and that would be looking just a single generation ahead, while forecasts looking half a century into the future are now quite common. Forecasting demand for meat – a commodity whose production depends on so many environmental, technical and economic variables and whose future level of consumption will be, as in the past, determined by a complex interaction of population and economic growth, disposable income, cultural preferences, social norms and health concerns – thus amounts to a guessing game with a fairly wide range of outcomes.

But FAO’s latest long-range forecast gives just single global values (accurate to 1 t) not just for 2030 (374 t) but also for 2050 (455 t) and 2080 (524 t). Compared to 2010, the demand in 2030 would be nearly 30%, and in 2050 about 55% higher. When subdivided between developing and developed countries, the forecast has the latter group producing in 2080 only a third as much as the former. These estimates imply slow but continuing growth of average per capita meat consumption in affluent countries (more than 20% higher in 2080 than in 2007) and 70% higher per capita meat supply in the rest of the world.

Standard assumptions driving these kinds of forecasts are obvious: either a slow growth or stagnation and decline of affluent population accompanied by a slow increase of average incomes; continuing, albeit slowing, population growth in modernizing countries where progressing urbanization will create not only many new large cities but also megacities, conurbations with more than 20 or 30 million people, and boost average disposable incomes of billions of people; advancing technical improvements that will keep in check the relative cost of essential agricultural inputs (fertilizers, other agrochemicals, field machinery) and that will keep reducing environmental impacts; and all of this powered by a continuing supply of readily available fuels and electricity whose cost per unit of final demand will not depart dramatically from the long-term trend.

Standard assumptions also imply continuation and intensification of existing practices ranging from large-scale cultivation of feed crops on arable land (with all associated environmental burdens) to further worldwide diffusion of massive centralized animal feeding operations for pork and poultry. Undoubtedly, more measures will be taken to improve the lot of mammals and birds in CAFOs. Many of them will be given a bit more space, their feed will not contain some questionable ingredients, an increasing share of them will be dosed less with unnecessary antibiotics and their wastes will be better treated. Some of these changes will be driven by animal welfare considerations, others by public health concerns, new environmental regulations and basic economic realities; all of them will be incremental and uneven. And while they might be cumulatively important, it is unlikely that their aggregate positive impact will be greater than the additional negative impact created by substantial increases in the expected demand for meat: by 2030 or 2050, our carnivory could thus well exact an even higher environmental price than today.

I would strongly argue that there is absolutely no need for higher meat supply in any affluent economy, and I do not think that improved nutrition, better health and increased longevity in the rest of the world is predicated on nearly doubling meat supply in today’s developing countries. Global output of as little as 140 t/year (carcass weight) would guarantee minimum intakes compatible with good health, and production on the order of 200 t of meat a year could be achieved without claiming any additional grazing or arable land and with water and nutrient inputs no higher than those currently used for growing just food crops.

And it could also be done in a manner that would actually improve soil quality and diversify farming income. Moreover, an additional 
100 t/year could be produced by using less than a fifth of the existing harvest of concentrate feeds, and it could come from less than a tenth of the farmland that is now under cultivation and that could be used to grow food crops. Even for a global population of eight billion, the output of 300 t/year would prorate to nearly 40 g of meat a year/capita, or well above 50 g a year for adults. This means that the average for the most frequent meat eaters, adolescent and adult men, could be 55 g/year, and the mean for women, children and people over 60 would be between 25 and 30 g/year, rates that are far above the minima needed for adequate nutrition and even above the optima correlated with desirable health indicators (low obesity rates, low CVD mortality) and with record nationwide longevities.

Global inequalities of all kinds are not going to be eliminated in a generation or two, and hence a realistic goal is not any rapid converging toward an egalitarian consumption mean: that mean would require significant consumption cuts in some of the richest countries (halving today’s average per capita supply) and some substantial increases in the poorest ones (doubling today’s per capita availability). What is desirable and what should be pursued by all possible means is a gradual convergence toward that egalitarian mean combined with continuing efficiency improvements and with practical displacement of some meat consumption by environmentally less demanding animal foodstuffs.

Such a process would be benefiting everybody by improving health and life expectancies of both affluent and low-income populations and by reducing the environmental burdens of meat production. Although the two opposite consumption trends of this great transition have been evident during the past generation, a much less uneven distribution of meat supply could come about only as a result of complex adjustments that will take decades to unfold. In the absence of dietary taboos, average meat intakes can rise fast as disposable incomes go up; in contrast, food preferences are among the most inertial of all behavioral traits and (except as result of a sudden economic hardship) consumption cuts of a similar rapidity are much less likely.

At the same time, modern dietary transition has modified eating habits of most of the humanity in what have been, in historic terms, relative short spans of time, in some cases as brief as a single generation. These dietary changes have been just a part of the general post-WW II shift toward greater affluence, and the two generations of these (only mildly interrupted) gains have created a habit of powerful anticipations of further gains. That may not be the case during the coming two generations because several concatenated trends are creating a world that will be appreciably different from that whose apogee was reached during the last decade of the 20th century.

Aging of Western population and, in many cases, their absolute decline appear to be irreversible processes: fertilities have fallen too far to recover above the replacement level, marriage rates are falling, first births are being postponed while the cost of raising a family in modern cities has risen considerably. By 2050, roughly two out of five Japanese, Spaniards and Germans will be above 60 years of age; even in China that share will be one-third (compared to just 12% in 2010!), and, together with many smaller countries, Germany, Japan and Russia will have millions (even tens of millions) fewer people than they have today.

We have yet to understand the complex impacts of these fundamental realities, but (judging by the German, Japanese and even Chinese experiences) continuing rise in meat demand will not be one of them. And while the American population will continue to grow, the country’s extraordinarily high rate of overweight and obesity, accompanied by a no less extraordinary waste of food, offer a perfect justification for greatly reduced meat consumption. Beef consumption is already in long-term decline, and the easiest way to achieve gradual lowering of America’s overall per capita meat intakes would not be by appealing to environmental consciousness (or by pointing out exaggerated threats to health) but by paying a price that more accurately reflects meat’s claim on energy, soils, water and the atmosphere.

Meat, of course, is not unique as we do not pay directly for the real cost of any foodstuff we consume or any form of energy that powers the modern civilizations or raw material that makes its complex infrastructures. Meat has become more affordable not only because of the rising productivity of the livestock sector but also because much less has been spent on other foodstuffs. This post-WW II spending shift has been pronounced even in the US where food was already abundant and relatively inexpensive: food expenditures took more than 40% of an average household’s disposable income in 1900; by 1950, the share was about 21%; it fell below 15% in 1966 and below 10% (9.9%) in the year 2000; in 2010, it was 9.4%, with just 5.5% spent on food consumed at home and 3.9% on food eaten away from home (USDA 2012b). The total expenditure was slightly less than spending on recreation and much less than spending on health care. At the same time, the share of overall food and drink spending received by farmers shrank from 14% in 1967 to 5% in 2007, while the share going to restaurants rose from 8% to 14%.

These trends cannot continue, and their arrest and a partial reversal should be a part of the affluent world’s broader return to rational spending after decades of living beyond its means. Unfortunately, such adjustments may not be gradual: while the FAO food price index stayed fairly steady between 1990 and 2005, the post-2008 spike lifted it to more than double the 2002–2004 mean, and it led to renewed concerns about future food supply and about the chances of recurring, and even higher, price spikes. Increased food prices in affluent countries would undoubtedly reduce the overall meat consumption, but their effect on food security on low-income nations is much less clear. For decades, low international food prices were seen as a major reason for continuing insecurity of their food supply (making it impossible for small-scale farmers to compete), but that conclusion was swiftly reversed with the post-2007 rapid rise of commodity prices that came to be seen as a major factor pushing people into hunger and poverty (Swinnen and Squicciarini 2012).

In any case, it is most unlikely that food prices in populous nations of Asia and Africa will decline to levels now prevailing in the West: China’s share of food spending is still 25% of disposable income, and given the country’s chronic water shortages, declining availability of high-quality farmland and rising feed imports, it is certain that it will not be halved yet again by the 2030s as it was during the past generation. And the food production and supply situation in India, Indonesia, Pakistan, Nigeria or Ethiopia is far behind China’s achievements, and it will put even greater limits on the eventual rise in meat demand. In a rational world, consumers in the rich countries should be willing to pay more for a food in order to lower the environmental impacts of its production, especially when that higher cost and the resulting lower consumption would also improve agriculture’s long-term prospects and benefit the health of the affected population.

So far, modern societies have shown little inclination to follow such a course – but I think that during the coming decades, a combination of economic and environmental realities will hasten such rational changes. Short-term outlook for complex systems is usually more of the same, but (as in the past) unpredictable events (or events whose eventual occurrence is widely anticipated but whose timing is beyond our ken) will eventually lead to some relatively rapid changes. These realities make it impossible to predict the durability of specific trends, but I think that during the next two to four decades, the odds are more than even that many rational adjustments needed to moderate livestock’s environmental impact (changes ranging from higher meat prices and reduced meat intakes to steps leading to lower environmental impacts of livestock production) will take place – if not by design, then by the force of changing circumstances.

Most nations in the West, as well as Japan, have already seen saturations of per capita meat consumption: inexorably, growth curves have entered the last, plateauing, stage and in some cases have gone beyond it, resulting in actual consumption declines. Most low-income countries are still at various points along the rapidly ascending phase of their consumption growth curves, but some are already approaching the upper bend. There is a high probability that by the middle of the 21st century, global meat production will cease to pose a steadily growing threat to the biosphere’s integrity.

What do you think?

Let me know in the comments.

Still curious? Buy Should We Eat Meat?: Evolution and Consequences of Modern Carnivory

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