The most slimming tortillas in the world

It's no secret that I'm an avid food gardener.  In the last two years, I've moved from exclusively growing vegetables to growing large quantities of staple calorie crops, such as potatoes, flour corn, and long-storing winter squash.

Why do I put so much effort into growing my own food, when I could buy it easily and cheaply at the grocery store?  There are a few reasons.  First and foremost, I enjoy it.  Second, it allows me to grow the healthiest and best-tasting ingredients possible (although I think you can compose a very healthy diet from grocery store foods).  Third, it saves a bit of money.  And fourth, it gives me a window into the world of my ancestors.

The fourth point is an important one for me, and it's why I can justify making tortillas the hard way.  What's the hard way, you ask?  Well, first you plant corn.  Then you water and weed it for several months.  Then you harvest the corn, shuck it and dry it on the cob.

Painted Mountain corn from my garden.

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The Hungry Brain: Book Update

In January of this year, I handed in a complete manuscript draft of my first book, The Hungry Brain, to my editor at Flatiron Books.  This book represents more than two full-time years of my life, and I can't wait for it to hit shelves.  It's markedly different from any other book in its category, and believe it has the potential to substantially change the public conversation on eating behavior and obesity.

In the process of writing The Hungry Brain, I read countless papers and interviewed 36 leading researchers in the fields of neuroscience, obesity research, and anthropology.  I had my brain scanned in an fMRI machine while looking at junk food.  I commissioned and compiled 47 illustrations, schematics, and graphs, mostly by a skilled medical illustrator named Shizuka Aoki.  Yet the book will be accessible to anyone who loves science.

This book is not about me or my world views.  It's not a conspiracy story about how everything we've been told is actually wrong, nor is it a critique of existing ideas about eating behavior and obesity-- although I do correct some misconceptions along the way.  It's about the incredible and rapidly evolving world of research that has so much to teach us about ourselves, but rarely trickles down into the public sphere in a useful form.

In interviews this year, I said I thought the book would be out around September 2016.  That was based on a rough estimate my agent gave me last year.  Sadly, it won't be out until first quarter 2017-- the gears turn slowly in the publishing industry.  But the good news is that Flatiron Books is using this time to do a great job of copyediting, interior design, cover design, and marketing, to make sure this book is as good as it can be, and gets into as many hands as possible.  I'll provide a better date estimate when I have one.

In the meantime, enjoy this short description of the book:

From an obesity and neuroscience researcher with a knack for storytelling, The Hungry Brain uses cutting-edge science to answer the questions: why do we overeat, and what can we do about it?

No one wants to overeat. And certainly no one wants to overeat for years, become overweight, and end up with a high risk of diabetes or heart disease--yet two thirds of Americans do precisely that.  Even though we know better, we often eat too much. Why does our behavior betray our own intentions to be lean and healthy? The problem, argues obesity and neuroscience researcher Stephan J. Guyenet, is not necessarily a lack of willpower or an incorrect understanding of what to eat. Rather, our appetites and food choices are led astray by ancient, instinctive brain circuits that play by the rules of a survival game that no longer exists. And these circuits don’t care about how you look in a bathing suit next summer.

To make the case, The Hungry Brain takes readers on an eye-opening journey through cutting-edge neuroscience that has never before been available to a general audience. The Hungry Brain delivers profound insights into why the brain undermines our weight goals and transforms these insights into practical guidelines for eating well and staying slim. Along the way, it explores how the human brain works, revealing how this mysterious organ makes us who we are.

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NuSI-funded Study Serves Up Disappointment for the Carbohydrate-insulin Hypothesis of Obesity

A new metabolic ward study tests the idea that lowering insulin via severe carbohydrate restriction increases metabolic rate and accelerates fat loss, independently of calorie intake.  Although carbohydrate restriction did modestly increase metabolic rate, it actually slowed fat loss.  One of the details that sets this study apart from previous studies is that it was funded by the Nutrition Science Initiative, an organization that was founded specifically to test the insulin hypothesis of obesity and related concepts.

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Two huge new studies further undermine the "obesity paradox"

The "obesity paradox" is the observation that people with higher fat mass sometimes have better health outcomes than lean people, including a lower overall risk of death.  Evidence has been steadily mounting that this finding may be a misleading artifact of the methods used to observe it.  Two massive new studies add to this evidence.

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A Serious Challenge to the 2012 Low-carbohydrate "Metabolic Advantage" Study

Warning: this post will be a bit more wonkish than usual, because I need to get detailed to make my points.  To read a summary, skip to the end.

In 2012, David Ludwig's group published an interesting RCT that suggested a substantial "metabolic advantage" resulting from a high-protein, very-low-carbohydrate diet (VLC) (1).  In other words, this diet led to a higher energy expenditure relative to a normal-protein, low-fat diet (LF) over a one month period (a low-glycemic-load, normal-protein diet was in the middle and not significantly different from the other two).  Resting energy expenditure (REE) was slightly but significantly higher on the VLC diet, and total energy expenditure (TEE) was elevated by a whopping 300+ kcal/day!  I covered the study at the time, describing it as "fascinating" and "groundbreaking", and calling for the study to be replicated so we can be more confident in its unexpected result (2).

This finding has been used by Ludwig, Gary Taubes, and others to support the carbohydrate-insulin hypothesis of obesity, although there is no evidence that the effect was mediated by insulin, and also no evidence that it was mediated by reduced carbohydrate rather than increased protein (3).

Since I published that post, my confidence in the finding-- and particularly the common interpretation of it that reducing carbohydrate intake to a very low level increases REE and TEE-- has gradually been eroding.  This is partially because other studies have generally reported that the carbohydrate:fat ratio of the diet has little or no effect on REE, TEE, or fat storage (4, 5, 6, 7, 8, 9, 10).

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Why some dogs (and humans) are born hungry

The brain is the central regulator of appetite and body fatness, and genetic variation that affects body fatness tends to act in the brain.  One important site of variation is the POMC gene, which codes for a signaling molecule that suppresses food intake.  A new study shows that Labrador retrievers often carry an inactive version of the POMC gene, causing them to be highly food motivated, obesity-prone-- and perhaps more easily trainable. 

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My Recent Paper on Linoleic Acid in Adipose Tissue

Linoleic acid (LA) is the predominant polyunsaturated fat in the human diet, and it's most concentrated in seed oils such as corn oil.  LA accumulates in fat tissue, and as with many of the nutrients we eat, it is biologically active.  In a new paper, we systematically review the studies that have measured the LA concentration of fat tissue in US adults over time.  We show that the LA concentration of fat tissue has increased by approximately 136 percent over the last half century.

Susan Carlson, PhD

In 2011, I posted a graph on my blog in which I summarized some of the studies that have measured the LA content of fat tissue in US adults over time (1).  It showed a remarkably consistent upward trend.  Last year, a University of Kansas nutrition researcher named Susan Carlson contacted me and asked if I had published my findings in a scientific journal, because she wanted to cite the trend in one of her papers.  I said I hadn't published them, but that I would love to do so together.

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Invincible Coffee: The Next Evolution of Joe

Warning -- Satire -- old April Fools post!

You've heard of Bulletproof Coffee, that mixture of coffee and butter that keeps you lean and supercharges your mental focus.

The problem with Bulletproof Coffee is that the butter forms a greasy oil slick on top of your coffee.  Yuck!  Is there any way to rescue Bulletproof Coffee?

Enter Invincible Coffee, the next evolution of Joe.

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Can Salt Increase Calorie Intake?

The debate rages on over whether dietary salt (NaCl) increases the risk of cardiovascular events, with no clear answer in sight.  Yet few people are paying attention to another, more insidious effect of salt: it may increase our calorie intake, and eventually, the size of our waistlines.

Introduction

Humans are born with specific hard-wired food motivations, which guide us to food properties that kept our ancestors alive and fertile in times past.  We have an instinctive attraction to sweetness because, in the world of our ancestors, it indicated ripe fruit or honey-- both important sources of calories and other nutrients.  Most of the other food properties we're instinctively drawn to, such as starch, fat, and glutamate, signify high-calorie foods.

Yet one of our hard-wired food motivations stands out from the rest: our attraction to salt.  Since salt is calorie-free, salt appetite is one of the few instinctive food drives that doesn't relate directly to acquiring calories.  Interestingly, salt is the only essential micronutrient (vitamin/mineral) we can taste at the concentrations normally found in food.  Not only our brains, but also our tongues, are hard-wired to seek salt above all other micronutrients.

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A Free Issue of Examine.com Research Digest

Examine.com is a website that provides unbiased information on supplements and nutrition.  They publish the Examine.com Research Digest (ERD), which reviews the latest studies in these areas.  I like ERD because it does a nice job of curating recent science, making it understandable and engaging for a broad audience, and explaining important background information.  They have no conflicts of interest because they don't sell anything except information.  I've been a scientific reviewer for ERD since the beginning.

Examine.com is celebrating its fifth anniversary today.  To celebrate, they offered to put together a custom issue of ERD using five of my favorite articles.  I chose articles I thought my audience would enjoy.  You can download your free copy here (PDF).

If you like it and decide you want to sign up for ERD, there is a link in the PDF, or you can visit this page.  They're having a sale today, so if you're thinking about joining, today is a good choice.  If you purchase through the links I provided, you'll be supporting Whole Health Source at no extra cost to yourself.

If you already have ERD, let me know how you like it in the comments.

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What I Eat

People often ask me what I eat.  I've been reluctant to share, because it feels egocentric and I'm a private person by nature.  I also don't want people to view my diet as a universal prescription for others.  But in the end, as someone who shares my opinions about nutrition, it's only fair that I answer the question.  So here we go.

In my food choices, I try to strike a balance between nutrition, cost, time efficiency, animal welfare, pleasure, and environmental impact.  I'm the chef of my household of two, and I cook two meals a day, almost every day, typically from single ingredients.  I prefer organic, but I don't insist on it.

Eggs from my hens

My diet changes seasonally because I grow much of my own food.  This started out with vegetables, but recently has expanded to staple foods such as potatoes, flour corn, and winter squash.  I also have a small flock of laying hens that turn table scraps, bugs, grass, and chicken feed into delicious eggs.

The primary guiding principle of my diet is to eat somewhere between a "Paleolithic"-style diet and a traditional agricultural/horticultural diet.  I think of it as a broad ancestral diet.  Because it's partially inspired by agricultural/horticultural diets, starch is the main calorie source.

My meals are organized around three food groups: a protein, a starch, and vegetables/fruit.  If any of those three are missing, the meal doesn't feel complete.  I'll start with those categories and move on from there.

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Is the "Obesity Paradox" an Illusion?

Over the last two decades, multiple independent research groups have come to the surprising conclusion that people with obesity (or, more commonly, overweight) might actually be healthier than lean people in certain ways.  This finding is called the "obesity paradox".  Yet recent research using more rigorous methods is suggesting that the paradox is an illusion-- and excess body fat may be even more harmful to health than we thought.

Introduction.  What is the obesity paradox, and why does it matter?

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Testing the Insulin Model: A Response to Dr. Ludwig

Dr. David Ludwig, MD, recently published a response to my critique of the carbohydrate-insulin-obesity hypothesis.  This is good because he defends the idea in more detail than I've encountered in other written works.  In fact, his piece is the most scientifically persuasive defense of the idea I can recall.

Before we dig in, I want to emphasize that this is science, not tribal warfare.  The goal is to arrive at the best answer, rather than to win an argument.  I'm proceeding in good faith, based on my belief that Ludwig and I are both serious people who care about science and human health, and I hope my audience will do the same.  That said, let's get to it.

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Always Hungry? It's Probably Not Your Insulin.

David Ludwig, MD, recently published a new book titled Always Hungry? Conquer cravings, retrain your fat cells, and lose weight permanently.  The book is getting widespread media coverage.  Ludwig is a professor of pediatrics at the Harvard Medical School and a professor of nutrition at the Harvard School of Public Health.  He's a pediatric endocrinologist, but his primary focus is research, particularly the impact of nutrition on hunger, calorie expenditure, and body weight.  Although I sometimes disagree with how he interprets evidence, he has made significant and useful contributions to the scientific literature in these areas, and I also support his efforts to find policy solutions to curb the intake of sweetened beverages and other junk foods.  In the grand scheme of things, he's an ally in the fight to improve the American diet.

Ludwig has written several high-profile op-ed pieces in recent years, both in the popular press and in scientific journals (1, 2).  He argues that our understanding of eating behavior and obesity may be all wrong, and that our focus on calories may be leading us away from the true cause of obesity: hormonal imbalance.  And the primary culprit is insulin.  You might recognize this idea, because it's similar to the one that science journalist Gary Taubes developed in his book Good Calories, Bad Calories.

According to this view, overeating is irrelevant.  We gain fat because our insulin levels are too high, leading our fat tissue to take up too much fat, and other tissues to take up too much glucose, causing our blood energy levels to drop and resulting in fat gain, hunger, and fatigue.  The ultimate cause of the problem is the rapidly-digesting carbohydrate and sugar we eat.  This idea is encapsulated by Ludwig's quote, "Overeating doesn't make you fat.  The process of getting fat makes you overeat" (3).

Here are eleven facts that may make you question this line of reasoning:
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How Much do You Know About Your Own Brain?

We tend to believe we're aware of what's happening in our own brains, and also in conscious control of our behavior.  But a growing body of neuroscience and psychology research demonstrates that most of what happens inside the brain-- including the processes that cause us to select and execute behaviors-- is beyond our conscious awareness.  This has important implications for our eating behavior, body weight, and health, as I explore in my upcoming book The Hungry Brain.

Let me give you a straightforward example that illustrates how little of our brain's activity we're aware of.  It focuses on information processing by the visual system, which is one of the best-understood systems of the brain.  I drew the basic facts of this example from a recent talk by the accomplished neuroscience researcher Marcus Raichle, who studies patterns of activity in the human brain.

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