• Your life and health are your own responsibility.
• Your decisions to act (or not act) based on information or advice anyone provides you—including me—are your own responsibility.


Anti-Nutritionism, L-Canavanine, And The Limitations of N=1 Self-Experimentation

What Is Nutritionism?

While I disagree with Gyorgy Scrinis (and the popularizer of the concept, Michael Pollan) on their proposed solution, I believe Scrinis’ concept of “nutritionism” as an error in dietary thinking has merit—and I doubt anyone in the paleo community would disagree.

Reducing food to its nutrient components could be called “nutritionism”, and it has probably become the dominant way of thinking about food and health, and of constructing healthy diets.

The nutrition industry has implicitly, if not explicitly, promoted nutritionism by continually framing most research studies and dietary advice in terms of these chemical-nutrient categories.

The rise of nutritionism is clear in one of the well-known sayings promoted by the food industry and some nutritionists: “There is no such thing as good and bad foods, only good and bad diets.” According to this argument, all types of foods, including junk food, have a place in a “balanced” diet.

Marketing foods and diets on the basis of their nutritional composition tends to take attention away from the quality and the type of foods being promoted.

Processed foods, for example, are often fortified with vitamins and minerals, or stripped of some of their fat, to enable such nutrient-content claims to be made. Nutrient claims on the labels of processed foods and drinks conceal the fact these foods are typically high in added fat, sugar, salt, chemical additives and reconstituted ingredients, and have often been stripped of a range of beneficial micro-nutrients and food components.”

High in protein, low in fat and too good to be true, Gyorgy Scrinis, Sydney Morning Herald, April 7, 2006

Nutritionism makes several unspoken assumptions:

  • We already know all the important nutrients and their functions.
  • The function of an isolated nutrient (even in a synthetic form not occurring in nature, e.g. folic acid) is exactly the same as its function in food, because…
  • There are no competitive or synergistic effects between the thousands of chemical compounds found in one bite of real food.
  • The effect of a food on health is reducible to its effects on the numbers obtained from cheap, easy tests like “BMI” and “total cholesterol”.
  • Therefore, so long as our diet contains the proper “nutrients”, we will be healthy and happy.

I doubt anyone in the paleo community disagrees with Scrinis (and Pollan) that nutritionism, in its modern form, is bunk. A diet of chicken nuggets, Twinkies, and Diet Coke is not nutritionally equivalent to a diet of fresh meat, fruits, and vegetables no matter how many supplements we take.

What Is Anti-Nutritionism?

Unfortunately it’s possible to fall into an analogous trap when pursuing a paleo way of life…a trap I call “anti-nutritionism”. Anti-nutritionism also makes several unspoken assumptions:

  • We already know all the important anti-nutrients and their functions.
  • The function of an isolated anti-nutrient is exactly the same as its function in food, because…
  • There are no competitive or synergistic effects between the thousands of chemical compounds found in one seed, sprout, fruit, or bite of plant or animal tissue.
  • Herbivorous, seed-eating mice—especially genetic knockout mice—are metabolically and biochemically the same as humans, and are excellent models for human digestion and metabolism.
  • Therefore, if I eat a food for six months and I don’t get any fatter or suffer obvious health problems, I can recommend it to others as healthy—and perhaps even paleo-compatible.

Food Doesn’t Want To Be Eaten

It’s tempting to believe that if a food we like doesn’t contain gluten, excessive omega-6 fats, or excessive fructose, that it’s fine to eat. However, all food has defenses against being eaten—because any plant or animal that was eaten before it reproduced failed to leave descendants!

This leads us to a tautological but astonishing conclusion. Every living thing on this Earth is the descendant of millions of generations of successful ancestors—not a single one of which was eaten, trampled, gored, poisoned, burned, drowned, starved, fell from a tree, killed by parasites or infection, or otherwise died before it managed to reproduce at least once.

“Being eaten” certainly qualifies as a reproduction-limiting event. Animals can hide, run away, or counter-attack—but plants cannot. Therefore, we might expect their defenses to involve being disgusting, poisonous, or indigestible—particularly for seeds, their agents of reproduction.

Fruit is the exception to the rule, but there’s an unspoken bargain involved: “eat this delicious, sweet fruit, but don’t digest the seeds…poop them out somewhere else.” As we’d expect, the seeds of most sweet fruits range from bitter to frankly poisonous.

Many books, websites, and scientific papers explore the biochemistry of anti-nutrients like gluten and gliadin (found in wheat and its relatives) and lectins (found in just about every plant seed), and I won’t rehash the biochemistry here. But just as our knowledge of the nutrients in food and their function is incomplete, our knowledge of anti-nutrients is, if anything, far more incomplete.

A Partial List Of Plant Toxins

Lectins, trypsin inhibitors, antigenic proteins, cyanogens, tannins, quinolizidine alkaloids, glucosinolates, saponins, phytoestrogens, non-protein amino acids…

Today’s Unsung Anti-Nutrient: L-Canavanine

To illustrate the limitations of the paleo community’s understanding of anti-nutrients, here’s an example I’ve never seen mentioned by any paleo source: L-canavanine.

(Update: Though it makes no appearance in the literature, apparently Dr. Loren Cordain has indeed been discussing L-canavanine in his speeches and presentations. Thanks to Pedro Bastos for the correction.)

“L-canavanine is a common non-protein amino acid found naturally in alfalfa sprouts, broad beans [also known as “fava beans”], jack beans, and a number of other legume foods [including sword beans] and animal feed ingredients [1] at up to 2.4% of food dry matter. This analog of arginine (Figure 1.) can also block NO synthesis [2-5], interfere with normal ammonia disposal [6,7], charge tRNAarg, cause the synthesis of canavanyl proteins [8], as well as prevent normal reproduction in arthropods [9] and rodents [10].

Canavanine has also been reported to induce a condition that mimics systemic lupus erythematosus (SLE) in primates [11,12], to increase antibodies to nuclear components and promote SLE-like lesions in auto immune-susceptible (e.g., (NZB X NZW)F1) mice [13].” (Brown 2005)

Stated plainly: canavanine “looks” like arginine, and is incorporated into our tissues like arginine…but the resulting proteins don’t function properly. And did I hear someone say “lupus”?

Arthritis Rheum. 1985 Jan;28(1):52-7.
Effects of L-canavanine on T cells may explain the induction of systemic lupus erythematosus by alfalfa.
Alcocer-Varela J, Iglesias A, Llorente L, Alarcón-Segovia D.

Alfalfa sprouts can induce systemic lupus erythematosus (SLE) in monkeys. This property of alfalfa sprouts has been attributed to their non-protein amino acid constituent, L-canavanine. Occurrence of autoimmune hemolytic anemia and exacerbation of SLE have been linked to ingestion of alfalfa tablets containing L-canavanine. In this report we show that L-canavanine has dose-related effects in vitro on human immunoregulatory cells, which could explain its lupus-inducing potential.

Rheum Dis Clin North Am. 1991 May;17(2):323-32.
Dietary amino acid-induced systemic lupus erythematosus.
Montanaro A, Bardana EJ Jr.
“In this article, we detail our experience with a human subject who developed autoimmune hemolytic anemia while participating in a research study that required the ingestion of alfalfa seeds. Subsequent experimental studies in primates ingesting alfalfa sprout seeds and L-canavanine (a prominent amino acid constituent of alfalfa) is presented. The results of these studies indicate a potential toxic and immunoregulatory role of L-canavanine in the induction of a systemic lupus-like disease in primates.”

L-canavanine, being an amino acid, is not deactivated by heat or cooking. So when we hear statements like “Beans are fine so long as you soak or sprout them”, it’s worth reminding ourselves that this isn’t even true according to the tiny fraction of legume biochemistry we understand—let alone the overwhelming majority we don’t.

Further Reading

J. Agric. Food Chem. 2003, 51, 2854−2865
Nonprotein Amino Acids of Plants: Significance in Medicine, Nutrition, and Agriculture
E. Arthur Bell

“Much more needs to be learned of the biological activity, the relative toxicities of these compounds to different organisms, and their nutritional value if we are to make the best use of them and the plants in which they are synthesized.”

Autoimmun Rev. 2006 Jul;5(6):429-35. Epub 2005 Dec 29.
Role of non-protein amino acid L-canavanine in autoimmunity.
Akaogi J, Barker T, Kuroda Y, Nacionales DC, Yamasaki Y, Stevens BR, Reeves WH, Satoh M.

Am J Clin Nutr November 1995 vol. 62 no. 5 1027-1028
Reply to NR Farnsworth
Victor Herbert

Also note that you’ll find a much-copied reference on the Internet claiming that canavanine toxicity is irrelevant to humans. Don’t be misled: it’s an article from a 1995 vegetarian journal which makes a host of blatantly false claims, such as “There is NO canavanine at all in other legumes that are commonly used as human food.”

Favism: A Postscript to the Fava Bean/Broad Bean Issue

Canavanine toxicity is distinct from vicine toxicity. Vicine (and its analogs covicin and isouramil) is a poison in fava beans that causes hemolytic anemia in susceptible people—a sometimes-fatal condition known as favism. Favism is caused by G6PDH deficiencies, common X-linked mutations which affect over 400 million people worldwide, mostly in Africa, the Middle East, and southern Asia.


The Limitations Of Self-Experimentation and N=1

Self-experimentation is very important, and we can learn much that is useful from it. For instance, trying to dial in carbohydrate intake can be a balancing act between weight loss, mood, and physical performance. People have found solutions to their own individual health issues via anything from egg yolks to beef liver to coconut oil to magnesium supplementation. And just coming up with a new repertoire of healthy, paleo-compatible foods to replace the pantry full of junk we used to eat involves extensive N=1 with new recipes—with immediate success not guaranteed.

However, there are limits to the knowledge we can accumulate. Stated plainly:

N=1 self-experimentation can tell us what works best for ourselves—within the limits of healthy eating, as defined by biochemistry and evolutionary context.

However, self-experimentation alone cannot tell us which foods are healthy to eat, because even a dramatic increase in lifetime risk is vanishingly unlikely to manifest itself during a few months of self-experimentation.

For instance, here’s a seemingly reasonable statement:

1. “I ate corn for six months, and I didn’t gain weight or feel worse. Therefore corn is healthy to eat.”

It’s certainly tempting to make these sorts of statements—but I find that temptation is best resisted. To illustrate why, here’s an equivalent statement that we can all agree isn’t reasonable:

2. “I started smoking six months ago, and I feel fine. Therefore smoking is healthy.”

Permit me to drive the point home with force:

3. “I started eating strontium-90 six months ago, and I haven’t got cancer yet. Therefore radiation exposure is healthy.”
4. “I started shooting heroin six months ago. It’s solved all my anxiety issues, and I’ve lost twenty pounds! Therefore shooting heroin is healthy.”
5. “I started having unprotected sex with Tanzanian hookers six months ago, and I feel great! Therefore unprotected sex with high-risk strangers is healthy.”

The reason we can identify the second through fifth statements as false is because we don’t trust the results of our own self-experimentation. We know that long-term observations show that smoking greatly increases our risk of several forms of cancer and heart disease; each Sievert of radiation exposure causes a 5-10% increase in cancer deaths (Strom 2003); heroin addiction is almost never a controllable vice; and HIV infection takes longer than six months to produce symptoms of AIDS—no matter how we feel in the short term.

No, I’m not directly comparing eating corn to smoking or unprotected sex with high-risk strangers! I’m demonstrating that even a substantial increase in lifetime risk is vanishingly unlikely to manifest itself within any period of self-experimentation. This is why anecdotes are useless when evaluating risk.

For example, my grandfather smoked two packs of cigarettes a day for over sixty years, dying in his 80s of a non-smoking-related illness…but that doesn’t change the fact that smokers contract lung cancer 15-20x more often than non-smokers (Thun et.al. 2008), and also suffer from all types of heart disease, many other cancers, renal damage, and impotence at a far greater rate than non-smokers. And while I’ve spent plenty of time making fun of weak associations extracted from known-bad data, I do find the evidence for negative health effects from regular smoking reasonably convincing—though perhaps of smaller magnitude than claimed by typical sound-bites.

In conclusion, it’s clear that anti-nutritionism makes it easy to fall into the trap of extrapolating N=1 beyond its limits. By assuming that we already know all the important anti-nutrients, we can easily convince ourselves that a clearly Neolithic food is healthy (or, at least, harmless) just because we don’t feel any obvious harmful effects from consuming it in the short term.

To answer such questions, we need to apply science, not N=1…

…and it is very likely that the answer will not be authoritative. Scientific answers are much more likely to be of the form “There are a lot of potential toxins, but we don’t know how bad they are for humans, either singly or in combination” or “It’s analogous to something that quickly causes pancreatic cancer in rats—at 10 times a realistic dietary dose.”

That’s where evolutionary context comes in, and where I use my general rule of thumb, previously seen here:

Eat foods you could pick, dig, or spear. Mostly spear.

The Takeaways: Now What?

My intent is not to encourage anyone to become overly fearful about eating the occasional bowl of ice cream or tarka dal! I understand that even functional paleo can feel somewhat limiting at times, and that nothing will make a fresh, hot Krispy Kreme not taste delicious.

What I’m doing is cautioning my readers that no interesting or useful information comes from arguments about whose N=1 is more authoritative; I’m reiterating my own commitment to careful, rational inquiry; and, most importantly, I’m hoping to communicate my own respect, humility, and awe as one infinitesimal part of our huge, beautiful and dizzyingly complex world and the multi-billion year history of life upon it. As I said nearly a year ago:

“There is an important difference between “We don’t know all the answers yet” and “Do what feels right, man.” These questions have answers, because humans have biochemistry, and we should do our best to find them and live by the results.”

The Paleo Identity Crisis: What Is The Paleo Diet, Anyway?

Meanwhile, I will continue to do my best to find interesting and useful information at the intersection of biochemistry and evolutionary context, and I will continue to explain it as best I can to you, my readers, here at gnolls.org.

And since I like to leave my readers with a few practical takeaways, here are some useful thoughts for when you start finding even functional paleo limiting or monotonous.

  • Consider what you’ve gained, not just what you’ve lost. Sure, you can’t just binge on half a dozen crullers anymore…but you can eat all the prime rib you want without any form of guilt. How cool is that?
  • If you’re stuck in a rut of monotonous food, try some new recipes. Yes, it’ll take some time and several tries to find and perfect a new dish you like as much as your current favorites. Here’s an endless source to get you started.
  • Cheat proudly. For the most part, the dose makes the poison…so unless cheating will start you on a binge, it’s better to say “I am going to eat these street tacos because they’re delicious and I want some” than to try to convince yourself that corn is paleo.
  • Cheat intelligently. Think of a cheat as dessert: once you’ve satisfied yourself with a complete meal, you can think about a Coke or a Reese’s. Otherwise you run the risk of your cheat replacing an entire meal—and once you’ve been paleo for a while, 1200 calories worth of Krispy Kremes will most likely make you feel like you’ve contracted Ebola Zaire.
  • Live in your body. The pleasure of junk food lasts until it slides down your throat: the pleasure of good health manifests itself 24/7 in better sleep, less pain, greater mental clarity and capacity, and greater physical ability. The strong, sleek, healthy body of an apex predator is a great place to be. Instead of medicating it into passivity or becoming a sessile peripheral to your computer and television, go outside. Climb a tree, kick balls, shoot baskets. Learn a new skill. Explore somewhere you’ve never been.

    There’s a big, bright, beautiful world out there: what are you waiting for?

Atop a Sierra peak that shall remain nameless

Live in freedom, live in beauty.


Yes, this one turned into another epic! Spread it like pollen with the new social clicky-popup-thing…and please support my continued efforts by making your Amazon purchases through my referral link. Did I mention that T-shirts are back in stock, in all sizes?

Why Snack Food Is Addictive: The Grand Unified Theory of Snack Appeal

snack \ˈsnak\ (n) – a small amount of food eaten between meals

As I’ve pointed out before, snacking makes you both fat and weak. And as the beginning of “Eat Like A Predator” states, much of the purpose of a paleo diet is to let you avoid snacking entirely:

Predators gorge and fast; prey grazes.

Rephrased for modern humans: Predators eat meals, prey grazes on snacks. This means you need to eat meals which will carry you through to your next meal, but that won’t make you tired or sleepy.

So why is it so difficult to stop snacking? Why is snack food so uniquely addicting? Why can we demolish entire tubes of Pringles, boxes of donuts, trays of chocolates, and bags of goldfish crackers, when we would never finish the same number of calories in the form of meat and vegetables?

It’s because snack food is a magic trick, played on our senses of taste.

Note: This article will help you understand what’s behind the concept of “food reward” that’s been making the rounds lately.

How Our Tastes Evolved: Understanding The Basic Tastes

Our tastes have been selected, over millions of years, to enjoy foods that are nutritious for us, and to dislike foods that are poisonous or not nutritious. Any humanoid whose tastes were not in accordance with healthy eating—for instance, an inability to distinguish plant toxins, or a lack of preference for calorie-dense fat over lean protein which we have a limited ability to process—would have died out over the hundreds of thousands of generations that separate us from our quadrupedal, forest-dwelling ancestors.

Here’s an excellent discussion of our taste receptors and their probable evolutionary purpose, adapted and modified from this intriguing article: “Why Did We Evolve A Taste For Sweetness?” by the Drs. Jaminet:

The five basic human tastes are sweet, salty, sour, bitter, and umami. Each taste detects either a nutrient class we need or toxins we should avoid.

  • Sweet: sugars. Mother’s milk, sweet fruits. Possibly also hydrophobic (fat-associated) proteins, i.e. a fat sensor: it’s impossible to taste fat by itself because it won’t bond to taste receptors.
  • Salty: electrolytes. Sodium and potassium are necessary for life.
  • Sour: acids. Attractive in small doses (wild fruits, lightly fermented food), aversive in large doses (spoiled food high in bacterial fermentation products).
  • Bitter: toxins. Again, usually OK in very small doses (e.g. cruciferous vegetables) but aversive in large doses.
  • Umami: glutamate (and some nucleotides). Basically a protein sensor.

(More information.)

Modern Technology, Paleolithic Tastes

The key to understanding snack food is to understand what foods were available to us in the Paleolithic, so that we can understand what our tastes are for. It’s impossible to overdose on sour or bitter because they’re aversive in large doses, so that leaves us with sweet (which also helps detect fat), salty, and umami.

Let’s examine fat: there was no such thing as “vegetable oil” (actually seed oil) in the Paleolithic. The only year-round source of dietary fat was animals, with nuts a secondary, seasonal source. Therefore, our taste for fat is primarily a taste for animal fat—including all the fat-soluble vitamins (A, D, E, K2-MK4) found in animal fat, and for which fat is necessary to absorb.

A wild banana. Small, starchy, and mostly seeds.

Sweetness was limited by lack of availability. Paleolithic fruits were much smaller and more bitter than modern varieties, which have been bred for sweetness and seedlessness to the point of being unable to reproduce without human help—and they would not have always been available at their peak of ripeness, as they’re eaten by many other animals too. Honey has always been rare. And as the Drs. Jaminet note, it is entirely possible that sweet taste receptors do double duty as animal fat detectors.

Salt was difficult to obtain, except for those who lived near the ocean. And as Parmesan cheese and kombu dashi hadn’t yet been created, umami was limited to its natural source—meat.

In conclusion, we can see that our taste receptors are primarily geared towards obtaining fatty meat and salt, with nuts and sweet fruit as occasional bonuses. So it’s not surprising that we enjoy salty, fatty meat and sweet fruits.

Snacking: The Supernormal Stimulus Of Taste

“Supernormal stimulus” is a technical term for something that’s so much better than reality that we prefer it…

…even when it’s obviously fake.

Niko Tinbergen and Konrad Lorenz found many examples of this in animals. Mother birds prefer to incubate fake eggs made of plaster if they’re larger and more brightly colored than their own eggs. Male stickleback fish will attack anything with a red underside, including toy boats.

This is because, in the evolutionary history of birds and sticklebacks, there haven’t been enough curious ethologists with plaster eggs and red-bottomed toy boats to make it important for these animals to tell the difference. If it’s egg-shaped and in your nest, sit on the biggest one, because it’s most likely to survive. If it’s in the water and red underneath, attack it, because it’s most likely another male.

Niko Tinbergen painting some supernormal stimuli.

A supernormal stimulus for humans.

Humans are no exception: we’re vulnerable to supernormal stimuli, too. Photoshop gives men rippling abdominals and women exaggerated curves. Comic book heroes are just as unrealistic as the heroines. Round yellow smiley faces communicate emotion more clearly and simply than a picture of a smiling person.

And in the evolutionary time of humans, there hasn’t been enough refined sugar, seed oil, and MSG to make it important for us to tell the difference between them and real food.

Here’s a startling experiment: rats prefer saccharine and sugar to intravenous cocaine, even after previously becoming addicted to cocaine:

PLoS ONE. 2007; 2(8): e698.
Intense Sweetness Surpasses Cocaine Reward
Magalie Lenoir,# Fuschia Serre,# Lauriane Cantin, and Serge H. Ahmed*

“…From day 7 onward, rats sampled lever C [cocaine] almost maximally, though slightly less than lever S [saccharin], before being allowed to make their choices (Fig. 1c). Thus, despite near maximal cocaine sampling, rats under the S+/C+ condition acquired a preference for lever S as quickly as rats under the S+/C- condition.”

“Our findings clearly demonstrate that intense sweetness can surpass cocaine reward, even in drug-sensitized and -addicted individuals.”

Characteristics Of Successful Snack Food

If you were to design a profitable and successful snack food, you’d want it to have several characteristics:

  • It would be made of cheap ingredients, allowing a high profit margin.
        Since our government heavily subsidizes industrial grain production, you’d make them of grains and grain products…corn, wheat, and soy. Mostly corn, because it’s so heavily overproduced that we’re forced, by law, to feed it to our cars!
  • It would be shelf-stable and require no preparation, so that it could be kept without refrigeration, taken anywhere, and eaten at any time.
        Therefore, you’d make it out of highly-processed ingredients that are shelf-stable, pump it full of preservatives so that it could survive for months in a vending machine, and enclose it in lots of disposable packaging so it wouldn’t get damaged in transit.
  • It would concentrate the tastes we’ve evolved to enjoy far beyond their natural amounts, and as much as our technology allows.
        This would be the supernormal stimuli of fatty, salty, umami, and sweet: MSG, crystalline sugar, seed oils, fruit juices, “natural and artificial flavors”.
  • Finally, it would not be satiating.
        No matter how much you ate, you would never be satisfied.

In other words, you’d create a movie set: something that looks like reality, but even better. More scenic, more exotic or mysterious or futuristic, more dramatically lit…

…and completely, utterly fake. The buildings have no interior, everything in the distance is just a matte painting or computer graphics, and it’s all built as cheaply as possible because it only has to last until the scene has been shot. All a movie set has to do is look nice for a few minutes, or a few seconds, from the right angle. You can’t live in a movie set, because that’s not what it’s built for…

…and you can’t live off snacks, because that’s not what they’re made for either.

The Magic Of Snacks, Part I: Taste Without Nutrition

Just as a movie set’s only constraint is to look good for a few seconds from a limited set of camera angles, a snack food’s only constraint is to taste good until it slides down your throat.

And that’s what technology allows us to do: create products (“snacks”) that tickle our taste receptors far more than real food can ever hope to—but that don’t come with the nutrition that selected us to crave those tastes in the first place.

This is the reason that the concept “eat whole foods, minimally processed” is generally sound: if whole foods taste good to us, it’s most likely because they contain nutrients we need, not because they’ve been engineered to tickle our taste buds. (Note that all modern fruits are heavily engineered products of thousands of years of careful breeding: read Dan Koeppel’s fascinating book “Banana” for a look at one typical example.)

The Magic Of Snacks, Part II: Taste Without Satiety

A pleasing taste isn’t enough to make an addictive snack food: as mentioned above, it must also be non-satiating. Steak and eggs are delicious—but we don’t have the urge to eat them until we’re sick.

There are many parts to satiety, but I’ll touch on what I believe to be the most important issue: protein satiation.

Protein Satiation

Complete protein is satiating. Our bodies absolutely require complete protein—but they also have a limited capacity to process protein in excess of our requirement. This shows up as what’s called “protein leverage”: people tend to consume food until they’ve ingested about 360 calories worth of complete protein. All other things being equal, if we eat foods high in protein, we consume less calories, and if we eat foods low in protein, we consume more. (You can read more about this issue in this AJCN article, and here.)

“Protein” is just chains of amino acids. “Complete protein” is protein containing all the essential amino acids—the ones we must eat because our bodies can’t make them—roughly in the proportions our body needs them.

Interestingly, egg protein is the standard by which protein quality is measured—probably because it takes the same kinds of protein (and other nutrients, like cholesterol) to make a healthy chicken as it does to make a healthy human. Any dietary advice that tells you to avoid eggs for any reason is, by definition, wrongheaded.

Therefore, if we want to sell an addictive and non-satiating food, we should keep it very low in protein (e.g. candy, cookies, potato chips). If it does contain protein, that protein should be incomplete—deficient in at least one essential amino acid—since the limiting factor for protein utilization is the least abundant essential amino acid.

Guess what? Corn and wheat, the foundation of chips, crackers, cookies, and over 90% of the breakfast aisle, are both deficient in lysine. And both zein (corn protein) and gluten (wheat protein) are prolamins, which are very difficult for our digestive enzymes to break down and decrease the digestibility of the associated starch.

Trivia fact: corn gluten meal (CGM) is used as an herbicide. Yum!

In support of this theory, you’ll note that “energy bars” are more satiating than candy bars, despite having a similar taste and number of calories…most likely because they tend to contain some amount of complete protein. (Though they make up for it by costing twice as much. You could be eating prime rib for what energy bars cost per pound. Think about it.)

Fat: The Satiety Potentiator

Fat is not satiating by itself—but it increases the satiation of the protein it’s eaten with. This is because fat slows gastric emptying and increases GI transit time. (More information here.) This is one reason why we can eat entire tubes of Pringles, but only a few eggs: Pringles contain fat and carbohydrate, eggs contain fat and complete protein.

Unless, of course, you’re Cool Hand Luke…

In support of protein satiation, a large hard-boiled egg contains about 75 calories, so that superhuman (and fictional) feat would involve 3750 calories’ worth of eggs. A can of Pringles contains about 900 calories.

50 eggs is just over four dozen eggs…3750 calories is just over four cans of Pringles. What’s easier to eat…a dozen hard-boiled eggs, or a can of Pringles?

The Nutrient Leverage Hypothesis

We can take the protein leverage hypothesis even farther, by extending it to other necessary nutrients. The unjustly neglected blog Fat Fiction makes the startling claim that nutrient deficiency is responsible for the obesity crisis, and cites (among other sources) an intriguing double-blind, placebo-controlled study of feeding multivitamins to obese Chinese women:

International Journal of Obesity (2010) 34, 1070–1077; doi:10.1038/ijo.2010.14; published online 9 February 2010
Effects of multivitamin and mineral supplementation on adiposity, energy expenditure and lipid profiles in obese Chinese women
Y Li1,4, C Wang2,4, K Zhu3, R N Feng1 and C H Sun1

After 26 weeks, compared with the placebo group, the MMS group had significantly lower BW [body weight], BMI, FM [fat mass], TC and LDL-C, significantly higher REE [resting energy expenditure] and HDL-C, as well as a borderline significant trend of lower RQ [respiratory quotient] (P=0.053) and WC [waist circumference] (P=0.071). The calcium group also had significantly higher HDL-C and lower LDL-C levels compared with the placebo group.”

Anyway, I recommend you read Mike’s “Two Minute Summary”. I’m not sure nutrient deficiency is everything, as he seems to be saying—but I believe he’s got hold of an important piece of the obesity puzzle that has been neglected in the rush to blame everything on insulin, and I encourage others in the ‘paleo’ field to build on his work.

Conclusion: Snacking Makes You Fat, By Design

Another supernormal stimulus.

In conclusion, we can see that “snack food” is designed to make us fat—by giving our taste buds a supernormal stimulus, while withholding the nutrition that has always gone along with that stimulus in evolutionary time. Just like the greylag goose that tries to sit on an egg-colored volleyball, or the stickleback fish attacking a red-painted toy boat, we can’t resist shoving highly processed, brightly packaged non-foods like cookies, donuts, crackers, corn chips, bread, cereal, and candy bars down our throats—

—especially when our rational minds are short-circuited by the label “All-natural!” or “Contains heart-healthy whole grains!” Our livers don’t care if fructose comes from Fanta or apple juice, our pancreas doesn’t care if glucose overload is accompanied by indigestible fiber and plant toxins (“whole grains”), and our eicosanoid pathways can’t tell if they’re clogged with omega-6 fats from Cool Ranch Doritos or Organic Multigrain Rainforest Eco-Chips.

Don’t believe the hype. If it takes multiple layers of brightly-colored packaging and a $multi-million, multi-media ad campaign to sell it, it’s not food. No one has to put meat or eggs in a brightly colored box with a cartoon character on it. I’m just sayin’.

What Should Humans Eat?

Eat foods you could pick, dig, or spear. Mostly spear.

Live in freedom, live in beauty.


Postscript: For those who want to know more, I explore our mechanisms of hunger and reward in detail in my epic series "Why Are We Hungry?" My older series on carbohydrate addiction starts here and explains some of its pathways.

If you enjoy my articles and want to support my continued efforts to inform and amuse you, my novel The Gnoll Credo is available from Amazon and my publisher in the USA, and from this list of international sellers. You can also make your other Amazon purchases through this link: it’ll cost you nothing, and I’ll get a small spiff. Thanks!